Disassemble the presentation of the global computer network Internet. Presentation on the topic "Global Internet"
Internet
Slides: 27 Words: 1058 Sounds: 0 Effects: 1Network information technologies. Internet. What is the Internet. The largest computer network. Why study the Internet. The history of the creation of the Internet. Client-server architecture. Low requirements for the client. Internet organization. Structure of the Internet. trunk operators. Internet protocols. Computers. TCP/IP protocol stack. Application layer protocols. Internet addressing. Network settings. Ports. Email. What IP addresses tell you. Fundamentals of the organization of the Internet. Domain name system. The unique identifier of the resource. URL format. Services on the Internet. History of creation. - Network Internet.ppt
Internet concepts
Slides: 11 Words: 641 Sounds: 0 Effects: 0Cafe. Internet. Sites. Search engines. Internet concepts. Server. Hosting. Teleconference. Email. E-mail address. Thank you. - Internet concepts.ppsx
global information network
Slides: 72 Words: 1815 Sounds: 0 Effects: 84Internet Word Wide Web. Hypertext and WWW. Global network Internet. Tools for working with the Internet. Browsers. Windows Internet Explorer 7.0. Computer networks. Means of communication. Computer networks and means of communication. Computer networks and means of communication. Computer networks and means of communication. Computer networks and means of communication. Computer networks and means of communication. Computer networks and means of communication. Mozilla Firefox. Computer networks and means of communication. Opera. Computer networks and means of communication. Computer networks and means of communication. Computer networks and means of communication. Computer networks and means of communication. - Global Information Network.ppt
Global network Internet
Slides: 41 Words: 3045 Sounds: 0 Effects: 0Computer networks, Internet and multimedia technologies. Internet. The history of the emergence and development of the Internet (prerequisites). Gradually there is a merging of various types of communication. Fiber optic lines are widely used. Increased international exchange. The history of the emergence and development of the Internet. In the 1970s, computers "understood" the protocol. ARPANET. The 1980s were a period of rapid growth for the Internet. Creation of WWW. The concept of global networks (examples of telecommunication networks). Purpose of the structural components of the network. The concept of global networks (networks of telecom operators). - Global Internet.ppt
Global information network Internet
Slides: 27 Words: 837 Sounds: 0 Effects: 0Global network Internet. Internet. Internet. History of creation and development. Creation of the ApraNet network. E-mail. US National Science Foundation Network. The structure of the Internet. Addressing computers on the Internet. Computer. Domain Name Service. TCP/IP protocol stack. TCP and IP protocols. Scheme of connection to the Internet. Internet services. Service. Email. Email protocols. Email address. Newsgroups. Group names. FTP service. World Wide Web Service. Basic concepts. hypertext documents. Uniform resource address. - Global Information Network Internet.ppt
Russian Internet audience
Slides: 19 Words: 888 Sounds: 0 Effects: 0Internet audiences in Russia. Internet audience sizes. What do we have. Population of the country. Methodology for conducting surveys. Internet audience measurement technique. Semiannual audience. Public opinion. Audience growth rates. Notes on growth rates. Audience and growth rates. Internet usage activity. Dynamics of Internet use activity. Conclusions from the activity dynamics diagram. Dynamics of Internet use. Conclusions about the rate of change in popularity. The final growth dynamics of the semi-annual audience. Dynamics of audience growth reserves. Research development. - Internet audience of Russia.ppt
media consumption
Slides: 19 Words: 658 Sounds: 0 Effects: 17Media consumption of Internet users. Television through the eyes of viewers. Media consumption of Russian citizens. Time budget. Media consumption of Internet users during the day. Content types. media content. TV content. Download vs consume online. Purchasing multimedia content via the Internet. Purchase of goods/services via the Internet. Placement of audio, video, photographic materials on the Internet. Sources of materials published on the Internet. Directions for the use of social networks. Volume of media consumption. Thank you for your attention. The popularity of Internet practices and the frequency of implementation. -
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The Internet is a global computer network that unites local, territorial and corporate networks WWW (World Wide Web - World Wide Web) or simply Web (Web).
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Global computer network Internet The Internet is a global computer network that unites many local, regional and corporate networks and includes tens of millions of computers. The Internet is actually a network database. Hyperlinks link hundreds of millions of documents together into a single network database. Internet
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The word Internet (English Internet), denoting a global computer network, arose as an abbreviation for Interconnected Networks - interconnected networks or "network of networks". Unlike local networks, its "elements" are not individual computers, but networks. Information on the Internet is stored on servers connected by high-speed communication lines (fiber optic, satellite). Almost all Internet services are based on the use of "client-server" technology: the client program on the user's computer requests information, the server returns a response.
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The World Wide Web The World Wide Web or "web" (Eng. And / And / And / = World Wide Web) is a service for accessing hypertext documents (web pages) stored on servers. Now WWW is the most popular Internet service. Hypertext is text that contains active links (hyperlinks) to other documents. Hyperlinks are usually underlined and highlighted in color (blue by default). If you left-click on a hyperlink, the document that the link points to is loaded into the browser window. On modern web pages, there is not only text, but also graphics, sound, video, and each element can be a hyperlink. Such documents are called hypermedia. A site (web site) is a group of web pages that are located on the same server, united by a common idea and linked using hyperlinks. To make the site available to other computers, a special program must be running on the server - a web server. Most popular web servers:
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Apache (httpd.apache.org), a free web server for various operating systems including Windows, Linux, Mac OS; IIS (www.iis.net) - commercial web server for Windows; nginx (sysoev.ru/nginx) is a free web server and mail server for large sites (there are versions for Windows and UNIX-like systems). Browser programs (Internet Explorer, Mozilla Firefox, Safari, Chrome, Opera) are used to view web pages on the screen. The browser sends a request to the web server containing the URL of the document (web page, picture, file, etc.), and the server responds with the requested data. The exchange takes place over the HTTP protocol.
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Ways to connect to a provider: The user gets access to the global network through a provider - a company whose local network is directly connected to the Internet. using a modem over a regular telephone line; the data exchange rate does not exceed 56 kbps, so this method is practically not used anymore; using an ADSL modem, which also uses a telephone line, but allows you to simultaneously talk on the phone and surf the Internet; the data transfer rate from the Internet to the user can reach 25 Mbps, however, additional equipment must be installed at the telephone exchange (a splitter that separates the low-frequency telephone signal from the high-frequency signal that transmits digital data); through the provider's local network (if it exists in your home); in this case, the telephone line is not used; using wireless modems (USB modems) that use the networks of cellular operators and work wherever mobile communications are available; the data transfer rate for 3rd generation networks (eng. 3G = 3rd generation) reaches 10 Mbps, and in 4th generation networks (4G) - up to 1 Gbps.
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New generations of mobile communications have been developed almost every decade since the transition from the development of the first generation of analog cellular networks in the 1970s (1G) to digital transmission networks (2G) in the 1980s. A sufficient amount of time passed from the start of development to actual implementation (for example, 1G networks were introduced in 1984, 2G networks - in 1991). In the 1990s, the 3G standard began to be developed. 4G generation networks based on the IP protocol began to be developed in 2000 and have been introduced in many countries since 2010. 4G is a generation of mobile communications with increased requirements. It is customary to refer to the fourth generation as promising technologies that allow data transmission at a speed exceeding 100 Mbps for mobile and 1 Gbps for fixed subscribers. LTE Advanced (LTE-A) and WiMAX 2 (WMAN-Advanced, IEEE 802.16m) technologies were officially recognized as fourth-generation 4G (IMT-Advanced) wireless communication standards by the International Telecommunication Union at a conference in Geneva in 2012. Highly mobile subscribers (e.g. trains and cars) should be provided with 100 Mbps and 1 Gbps should be provided with low mobility subscribers (e.g. pedestrians and fixed subscribers)
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Working sketch diagram of the first global network ARPA NETWORK The first network consisted of 4 computers
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A Brief History In the 1960s, the US Department of Defense began developing a computer data communications system called the Advanced Research Projects Agency Network (ARPANET). This project was based on the following ideas: the network unites computers with different hardware and software;
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when connecting a new network, no alteration of the existing part is required; there is no single center (such a network is called distributed), this ensures survivability in the event of failure of any node; packet data transmission: the transmitted data is divided into small packets, one communication line is used for the simultaneous transmission of several blocks of data.
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In 1969, the first data exchange took place over a network between computers installed at the University of California and the Stanford Research Center. In 1971, an e-mail program was created, which immediately became very popular. Beginning in 1973, universities and colleges not only in the United States, but also in Europe, have been connected to the new network. In 1983, the network is divided into two parts: the military network MilNet and the public network, which is called the Internet. The history of the Russian Internet begins in 1990, when the Relcom postal network was organized - the first provider in the Soviet Union. In 1991, British scientist Tim Bernes-Lee developed a data exchange system in the form of hypertext - text with active links to other documents. Now it is called the World Wide Web (eng. WWW = World Wide Web) and is the most powerful service on the Internet. Many mistakenly believe that the Internet and the World Wide Web are one and the same. In fact, this is not the case, because there are other services on the Internet - e-mail, file sharing, chat rooms, forums, etc.
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Graphical depiction of links between Internet networks. Only connections between servers are shown
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The Internet functions and develops thanks to the use of a single data transfer protocol TCP/IP. Data transfer protocol TCP/IP Internet Protocol (IP) - routing protocol - provides routing of IP packets, i.e. delivery of information from the sending computer to the receiving computer. Transmission Control Protocol (TCP) - a transport protocol - provides splitting of transmitted files into IP packets in the process of transmission and assembly of files in the process of receiving.
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In order to account for the millions of PCs on the network use unique codes, the TCP/IP network protocols. This number consists of 4 sections, each from 0 to 255 198.168.10.65 Provider - a person or organization, an Internet service provider Each computer connected to the Internet has its own unique 32-bit IP address (Internet Protocol). Possibly 232 = 4,294,967,296 IP addresses written as four decimal numbers from 0 to 255 separated by a dot: 123.45.67.89. Internet Addressing
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Protocols You already know that the source and destination must use the same protocol to transmit information, a set of rules and conventions that govern how data is exchanged on a network. The Internet has adopted the TCP/IP protocol, developed in 1974, as a standard. Generally speaking, this is not one protocol, but a whole family, the name of which comes from the two most important protocols - TCP (English Transfer Control Protocol - transmission control protocol) and IP (English Internet Protocol - Internet Protocol). Let's try to figure out why you need to use several protocols to work on the Internet. Suppose a browser on computer A requests a web page from a server located on computer B. The "conversation" between the browser and the server is via HTTP (HyperText Transfer Protocol). The browser and web server cannot communicate directly. To send a request to a server, the browser passes the server's address and the request text to the operating system, which invokes the TCP protocol driver.
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The task of the TCP driver is to establish a connection with a remote computer and ensure the delivery of data. The transmitted data block is divided into packets (the packet size usually does not exceed 1.5 KB), and each packet is transmitted to the next level - the IP protocol driver, which sends it to the network at the specified address Usually, when working on the Internet, computers A and B are not directly connected , so the task of the IP protocol is to determine the router node to which the packet needs to be sent so that it reaches computer B. When the route is determined, the packet (with added service information) is transmitted to the physical layer (for example, to a network card), where it is simply transmitted like a string of bytes. Physical layer protocols can be anything, they are not defined in the standard. The IP protocol does not guarantee the delivery of packets, so the TCP driver must (using the established connection) check that the data has been received and retransmit the packet if it fails. At the other end of the connection, the TCP driver "collects" the packets into a single block of data and passes it to the application layer (the request reached the server). Routers exchange information with each other, reporting the failure or connection of some sections of the network. The routing tables are updated automatically so that packet routing takes into account the actual network structure at the time.
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Classes of IP addresses There are 5 classes of IP addresses - A, B, C, D, E. An IP address belongs to one class or another is determined by the value of the first octet (W). The correspondence between the values of the first octet and the address classes is shown below. IP address class A B C D E First octet range 1-127 128-191 192-223 224-239 240-247
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Ranges: Class C To A 0.0.0.0 127.255.255.255 B 128.0.0.0 191.255.255.255 C 192.0.0.0 223.255.255.255 D 224.0.0.0 239.255.255.255 E 240.0.0. 0 255.255.255.255
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Thus, the Internet uses a four-layer system of protocols, each of which "does its own thing": 1) the application layer - the format of requests and responses exchanged between programs; 2) transport layer (TCP) - rules for packet transmission of data blocks without regard to their content; 3) network layer (IP) - route selection rules for individual packets without a guarantee of their delivery; 4) physical layer - the rules for the transmission of individual bytes over a cable, fiber optic or other communication line.
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At the application level (which is "closest" to the user), the most commonly used protocols are: HTTP - for transferring web pages; FTP - for file transfer; SMTP - for sending e-mail messages to the server; POP3 or IMAP - to receive email messages from the server. There are other protocols (for chat rooms, newsgroups, etc.), but they all use TCP and IP, respectively, at the transport and network layers
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212.96.118.82, 256*256*256*256 Internet addresses IP addresses Any two computers on the Internet can communicate with each other. To do this, each of them must have a unique address. From the "point of view" of computers, it is more convenient to work with numerical addresses, each of which occupies the same place in memory. These addresses (called IP addresses) consist of four numbers ranging from 0 to 255, for example, 192.168.104.115
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These numbers encode the network number and computer number on the network. In order to isolate these two parts from an IP address, wildcards are used. The mask is also four numbers in the range 0-255, but it is built in a special way, according to the principle of “n ones, then zeros” in binary code. For example, the mask is 255.255.255.0 Due to the rapid development of the Internet, the addresses that can be used in such encoding will soon not be enough for everyone. Therefore, it is assumed that there will be a gradual transition to the new (sixth) version of the IP protocol, which is designated as IPv6. It has 128 bits for each address, not 32. Already, there are more than 1600 networks that use IPv6; it is supported by all modern operating systems and hardware manufacturers. Full transition to IPv6 will take several years, it will require a lot of money and the replacement of all obsolete devices. Generally speaking, an IP address is assigned not to a computer, but to an interface - a data transmission channel (network card, modem). Therefore, one computer can have several IP addresses, for example, if it has two network cards installed (or a network card and a modem).
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RU STAVROPOL ALRUS alrus.stavropol.ru Top-level domain - Country Low-level domain - City Low-level domain - Node .
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Top-level domains are of two types: geographic (two-letter - each country has a two-letter code) and administrative (two-three-letter). Domain name system Microsoft's main server www.microsoft.com microsoft Administrative Organization type com Commercial edu General education gov US government int International mil Military US net Computer network org Non-profit Country Canada Germany Japan Russia former USSR England / Ireland USA Geographic ca de jp ru su uk us com www
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Com - commercial Org - non-commercial Gov - government Edu - educational Mil - military Net - networking Biz - business; Info - information sites; Name - personal sites; Museum - museums; Primary top-level domain names
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ru - Russia au- Australia by - Belarus ca - Canada de - Germany fr - France jp - Japan In addition, each country has its own two-letter first-level domain Main top-level domain names for countries
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The distribution of IP addresses and first-level domains is handled by the international organization ICANN (Internet Corporation for Assigned Names and Numbers). Russian domain.ru was registered in 1994. A free second-level domain can be registered by anyone for a small fee. Such services are provided by special organizations - domain name registrars, for example, RU-Center (nic.ru). Third level domains can often be obtained for free. For example, the site narod.yandex.ru provides everyone with a place for a site and a third-level domain like ivanov.narod.ru.
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Previously, only Latin letters, numbers and hyphens were allowed in domain names. Now you can register domains containing other UNICODE characters, for example, letters of the Russian alphabet. Domain.rf is assigned to Russia, in which everyone can register second-level domains. Thus, two systems of addresses are currently used on the Internet: IP addresses and domain names. To establish a correspondence between them, special servers called DNS servers store tables consisting of IP address - domain name pairs. Their task is to return an IP address for a given domain name (or vice versa) at the request of a client computer.
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When registering an address, the provider provides the following data: IP address Netmask Name server Gateway Phone number of the provider's modem Instructions for logging in, etc.
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In order for the computer to be able to communicate with the network, the network card (or modem) settings specify the IP address, network mask, and DNS server address. Sometimes this data is determined automatically when you connect to the provider's network. When you enter a website address (domain name) into your browser's address bar, a query is first sent to the DNS server, the purpose of which is to determine the server's IP address. If successful, a request is made to obtain a web page, with the IP protocol driver using the received IP address rather than the domain name. Note that one domain name can correspond to several IP addresses. this technique is used to distribute the load on sites with a large number of visitors (for example, www.yandex.ru, www.google.com). Thus, the correspondence between domain names and IP addresses can be described as "many-to-many": several domain names can be associated with one IP address and vice versa.
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Resource address (URL) Not only does every computer on the Internet have an exact address, but so does every document. For such an address, the English abbreviation URL = Uniform Resource Locator is most often used. A typical URL consists of four parts: protocol, server name (or its IP address), directory, and document (file) name. Such a recording system was invented in 1990 by the creator of the World Wide Web T. Bernes-Lee. For example, the address http://example.com/doc/new/vasya-new.htm includes the HTTP protocol - a protocol for exchanging hypertext documents (this is a web page); server domain name example.com; directory on the server /doc/new; the file name is vasya-new.htm.
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In other words, to access the vasya-new.htm document, which is located in the /doc/new directory on the example.com server, you need to use the HTTP protocol. Sometimes the directory and filename are not specified, such as http://example.com. This means that we are accessing the main page of the site. It may have different names, depending on the server settings (most often - index.htm, index.html, index.php). FTP is often used to download and upload files, then the document address looks something like this: ftp://files.example.com/pub/new/vasya-new.zip
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Examples of Internet addresses https://www.yandex.ru https://www.mail.ru http://www.rp5.ru/ http://ashk.rf http://support.kaspersky.ru/ Protocol transmissions Web (Internet) zone
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Basic Internet services Storage and provision of information E-mail Search engines Voice and video communication File transfer Forums and blogs Social networks Online stores Electronic payment systems, etc.
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A feature of the modern web is the involvement of users in filling sites with information and its correction. This led to the emergence of the term "Web 2.0", which is sometimes used to refer to the current stage of development of the World Wide Web. Sites using Web 2.0 technologies usually require user registration, which requires a valid e-mail address. Anyone can create a "private zone" with their own settings and store files, photos, videos, notes there. Others may comment on these materials. Users unite in groups (communities) in order to discuss issues of interest to them together. Often participants can evaluate each other's posts, thus changing the "reputation" (or "karma") of the participants, some rivalry appears
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Social networks: VKontakte (vk.ru), Odnoklassniki (www.odnoklassniki.ru), Facebook (www.facebook.com) have become a place for many to communicate with friends and classmates. Special sites have appeared where users can blog - online diaries (www.livejournal.com, - www.blogspot.com). The influence of blogs has increased so much that they have become equated with the media / Actively developing wiki systems (eng. wiki) - websites, the structure and content of which users can change using the tools that are on the site itself. The most famous wiki site is the free encyclopedia Wikipedia (the Russian version is hosted on the site ru.wikipedia.org
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Domain Names Unlike computers, humans are not comfortable working with numeric addresses. They are hard to remember, it is easy to make a mistake when entering an IP address, and sometimes it is quite difficult to notice it. Therefore, in 1984, the Domain Name System (DNS = Domain Name System) was developed, which allowed the use of symbolic site names, for example, www.mail.ru. Domain (English domain - area, district) is a group of symbolic addresses on the Internet. Domains form a multi-level structure (hierarchy, tree), nested into each other, like nesting dolls. In some ways, such a system resembles a postal address, which indicates the country, city, street, house, apartment. The point at the root of the tree is the root domain. Top-level domains (they are called domain zones) can indicate a type of organization, for example
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Searching for information on the Internet The Internet now contains a huge amount of data, while finding the information you need is sometimes quite difficult. A search engine is a website that is designed to search for information on the Internet. At the beginning of the development of the Internet, when there were few sites, webmasters (site creators) compiled lists of links to interesting sites. When there were a lot of links, they began to be grouped by topic. As a result of the development of this idea, catalogs appeared. A web directory is a list of links to sites broken down by topic with a brief description of them. Catalogs usually use a multi-level grouping of links (tree): each of the major topics (News, Science, Education, etc.) has sections, sections have subsections, etc. Yahoo (www.yahoo.com), founded in 1995, was the first major directory site. The largest of the Russian directories are Yandex-catalog (yaca.yandex.ru) and [email protected] (list.mail.ru). Catalogs are filled manually by human experts (catalog editors), each of whom is responsible for a specific section. In addition, webmasters can offer editors their sites for inclusion in the catalog (for free or for a fee).
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A search engine is an automatic system that stores information about all web pages known to it and, upon request, returns the addresses of those of them where the keywords entered by the user are found. The robot browser of a search engine (often called a "spider", English crawler) pumps out web pages from sites, following all the links they encounter. Keywords are a set of words and expressions that reflect the required information. The search robot uses the index to find those pages where these words occur. Each search engine has its own language, which allows you to make complex queries, for example, exclude certain keywords from the search or search for one of a given set of words. In many systems, the symbol | is used to indicate the logical operation "OR" (one of the specified words is needed), and the symbol & is used for the logical operation "AND" (both words are needed). If you need to find a phrase, in the query it is taken in quotation marks. Typically, a search robot finds thousands of pages that match a query. They are issued to the user in the order determined by the developers. Most often, citation is taken into account - the number of links from other sites to this page; the more links, the higher the "rank" of this page and the higher it is located in the search results.
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5. What family of protocols is used on the Internet? 6. Explain why there are multiple layers of protocols. Tell us about the role of protocols at different levels. 7. What is the role of router nodes? 8. How is guaranteed delivery of messages on the Internet? 9. Name the most famous application layer protocols. Where they are used Control questions How is client-server technology used on the Internet? What is a provider? Tell me how you can access the Internet. What are the advantages and disadvantages of different methods? What ideas formed the basis of the global computer network?
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How much memory space does an IP address take up? 3. Do you think two computers can have the same IP address? Justify the answer. 4. What IP addresses are used for LANs? Why does it become necessary to migrate to IPv6? What is a domain? In the form of what structure can the domain name system be represented? What domains can you register (if available)? Do you think that domains with Russian letters will be popular? Justify the answer. What is a DNS server? What functions does it perform? What is a URL? What parts does it usually consist of?
Composition of the Internet 2 WWW. (World Wide Web) E-mail () File servers (FTP) Teleconferencing (UseNet) Real-time communication systems (ICQ)
WWW - World Wide Web 3 The World Wide Web (World Wide Web) is an information system, the main components of which are hypertext documents (pages created using the HTML hypertext markup language). Web documents are accessed using web servers. The virtual world of the WWW is populated by millions of documents residing on hundreds of thousands of servers. The task of the WWW-traveler is to find among them the one that contains the necessary information, and to read it with the help of the viewer, and for this the viewer must know the exact location of this document. It is uniquely identified by the server address, port number, directory name, and file name with this document.
4 In order to navigate the Web, you need a browser program that can establish a connection with the server on which the website is located and provide the user with access to its resources. Such programs are called browsers, or navigators. In order to navigate the Web, you need a browser program that can establish a connection with the server on which the website is located and provide the user with access to its resources. Such programs are called browsers, or navigators. The most common browsers are Microsoft's Internet Explorer and Netscape's Netscape Navigator. Web document addresses (URLs) locate resources on the Internet and share the same basic structure.
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6 A protocol is a set of rules by which client-server interaction takes place. The "native" WWW protocol is called http. In addition to http, WWW clients can communicate with servers that support the ftp, gopher, and some other protocols. The protocol name is separated from the rest of the URL by a colon. In the protocol name, uppercase Latin letters and their corresponding lowercase letters are equivalent.
7 Server address: The beginning of the address is marked with two slashes //. It consists of several parts (not necessarily four, as in our example) - the so-called subdomains. Subdomains, which are combinations of letters and numbers, are separated by dots, and the "reference of addressee coordinates" from larger to smaller subdomains occurs from right to left. As in the name of the protocol, in the server address, uppercase Latin letters and their corresponding lowercase letters are equivalent
Edu is a top level domain. It denotes either a country code or, as in this case, a network code. edu is the code for the network of higher education institutions in the United States. The following top-level domains are also often found: gov - US government organizations, mil - US armed forces, com - commercial organizations, net - Internet network services, org - non-profit organizations, su - CIS countries, ru - Russia.
Uiuc.edu is a second-level subdomain. Second-level subdomain names are approved in accordance with the rules developed by top-level domains. In this case, the abbreviation means University of Illinois at Urbana-Champaign.
Scs.uiuc.edu is a third level subdomain. Third-level subdomain names are approved in accordance with the rules developed by second-level domains. In our example, scs means School of Chemical Sciences.
Subdomain of the fourth, in this case, the youngest level. Likewise, fourth-level subdomain names are approved according to rules developed by third-level domains. In our example, the subdomain is named www because the WWW server is located on this machine.
12 The port number is expressed as a positive integer and is separated from the address by a colon. A port is like a "door" through which you can enter the server. A server may have multiple ports available; if the WWW server port number is 80, then it can be omitted from the URL.
E-mail 15 E-mail (English, from English electronic mail) technology and services provided by it for sending and receiving electronic messages (called "letters" or "e-mails") over a distributed (including global) computer network. An email is a plain text file containing the recipient's email address and the body of the email.
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Working with e-mail Inbox - contains letters received by the addressee; Outbox - contains letters sent by the addressee, from the moment they were created until the moment they were delivered from the local computer to the mail server; Sent - contains all messages delivered to the mail server; Deleted - contains deleted messages; Drafts - contains letter drafts. 17
Mailbox A mailbox is a section of the mail server's external memory reserved for a subscriber. The mailbox has a unique name; the owner gets access to his mailbox through the password: 18
Email exchange rules. The email should not contain a large text message, if necessary, it is better to attach a text file; Attached letters must have the volume in accordance with the instructions; Be sure to use archivers to pack attachments; To enhance the emotionality of the letter, you must use emoticons. 20
Teleconference 22 Teleconference: comfortable communication Communication is the interaction of individuals or social groups, which consists in joint activities, direct exchange of skills, abilities, experience, information and satisfies the needs of a person in contacts with other people. A teleconference (UseNet) is a system for exchanging information between multiple users.
On-line communication 23 On-line communication systems (chat? ICQ) are specialized tools that allow real-time communication between users via computer communication channels. Chat (English chat to chat, chatter, conversation) is a means of exchanging messages over a computer network in real time, as well as software that allows you to organize such communication. A characteristic feature is communication in real time or close to it, which distinguishes chat from forums and other "slow" means. The word chat usually refers to group communication, although one-on-one text exchange through instant messaging programs, such as ICQ or even SMS, can also be included. Chat (English chat to chat, chatter, conversation) is a means of exchanging messages over a computer network in real time, as well as software that allows you to organize such communication. A characteristic feature is communication in real time or close to it, which distinguishes chat from forums and other "slow" means. The word chat usually refers to group communication, although one-on-one text exchange through instant messaging programs, such as ICQ or even SMS, can also be included. Databases with remote access 28 People's Library Biographies of famous people Science and education Collection of abstracts
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Bozhenko Anastasia
The presentation contains information about the basics of the global computer network Internet
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Global computer network "Internet" Completed by: 9th grade student Anastasia Bozhenko Supervisor: teacher of computer science and ICT Yaltantseva V.V. SCOU RO boarding school of the 5th type in the city of Zernograd
Plan The history of the emergence of global computer networks The basic concept of global computer networks Equipment used in global networks Internet connection Internet services (services) Terminal mode E-mail Usenet teleconferences World Wide Web service Domain Name System (DNS) FTP file transfer service Gopher shell Instant messaging services and instant messengers
The history of the appearance of global computer networks In 1969, the ARPAnet computer network was created in the United States, uniting the computer centers of the Ministry of Defense and a number of educational organizations. On January 1, 1983, the ARPANET switched to the TCP / IP protocol stack, which is still successfully used to connect networks. It was in 1983 that the term "Internet" was assigned to the ARPANET.
Basic concepts of global computer networks The Internet is a global computer network that unites many local, regional and corporate networks and includes tens of millions of computers. The official birth date of the Internet is January 1, 1983. On this day, it was decided to transfer the ARPA network to the TCP / IP protocol. The Jargon File gives the "date of birth of the Internet" 1969, the transition from NCP/IP to TCP/IP - 1982, the appearance of the first DNS - 1983.
TCP / IP protocol The TCP / IP protocol has many features that give it an advantage over other protocols: the ability to fragment packets a flexible addressing system that makes it easier to include networks of other technologies in the global network
Global network equipment A modem is a device for interfacing a computer with a telephone line that receives signals from a computer and converts them into a form suitable for the telephone network and vice versa. Types of modems: internal - has the form of a board built into the PC system unit; external - a separate device connected, on the one hand, to one of the PC connectors, and on the other hand, to the telephone network.
Connecting to the Internet using ADSL technology ADSL (Asymmetric Digital Subscriber Line - asymmetric digital subscriber line) is a technology that turns standard analog telephone lines into high-speed access lines. This connection, despite some of its shortcomings, remains the most popular today.
Wireless Internet Wi - Fi connection (Wireless Fidelity - "wireless accuracy") is very convenient and fast enough (up to 100 Mbps). To set up a connection to the Internet via Wi-Fi, you will need special equipment. Firstly, receivers must be installed on the computers that you want to connect (they are built-in on most modern laptops), and to create your own wireless network, you will need devices that “distribute the Internet” (access points).
Mobile Internet This connection is very convenient in cases when you need to access the Internet away from telephone sockets or outside the coverage area of a Wi-Fi network. Today, leading mobile operators have special USB modems into which a SIM card is inserted. This device looks like a regular flash drive.
4G Internet Connecting to the Internet using this technology is quite simple: it is enough to have a special 4G modem device. The only difficulty is the small coverage area of these networks, unlike mobile communications. Whatever Internet connection you choose, the main thing is to make it safe. If you use Wi-Fi wireless networks, then remember that the network must be password protected, otherwise anyone within range of the network can freely use your Internet connection.
Internet Services Telnet World Wide Web E-mail Usenet newsgroups Domain Name System (DNS) File Transfer Service FTP Gopher Shell Instant Messaging and Messenger Services
Telnet This service provides interaction with a remote computer. By establishing a connection using Telnet, the user gets the opportunity to work with a remote computer, as with "his own". The Telnet service has not been used by most users lately. Many information systems previously accessible exclusively via Telnet are now accessible from the World Wide Web.
WWW (World Wide Web) In 1991, the European Laboratory for Particle Physics (CERN) in Switzerland announced the creation of a new global information environment, the World Wide Web. The creation of the World Wide Web, based on hypertext technology and the HTTP application protocol for transmitting Web pages, is a major event in the history of the Internet. Web pages are created using a special HTML language. WWW (World Wide Web) is the most popular service on the Internet. WWW is the basis of the Internet, it is a distributed system of hypermedia (hypertext), in which documents are hosted on Internet servers and linked to each other by links.
E-mail (E-Mail) E-mail is similar to regular mail, and it is very easy to get used to using it. Typically, email reaches anywhere in the world in a matter of minutes. Just like a fax, it allows you to transmit not only text, but also an image, but you do not use long-distance or international telephone communications, and image quality does not deteriorate during transmission.
Usenet Usenet is a computer network used to communicate and publish files. Usenet consists of newsgroups to which users can post messages. Messages are stored on servers that exchange them with each other. Usenet has had a great influence on the development of modern web culture, giving rise to such widely known concepts as "nickname", "smiley", "signature", "moderator", "trolling", "flood", "flame", "ban" , "FAQ" and "spam". Usenet is part of the Internet, not a separate network. Usenet is accessed via the NNTP protocol.
Domain Name System (DNS) DNS (English Domain Name System - domain name system) - a computer distributed system for obtaining information about domains. Most commonly used to obtain an IP address from a host name (computer or device), obtain information about mail routing, serving hosts for protocols in a domain (SRV record). A distributed DNS database is supported by a hierarchy of DNS servers that communicate over a specific protocol.
FTP Service The FTP service is widely used for file sharing on the Internet and local networks. It runs on a specialized FTP protocol (file transfer protocol), which is intended only for file transfer and is well suited for this task.
Gopher Shell Gopher is an Internet capability integrator. It allows you to use all the services provided by the Internet in a convenient form. The shell is organized in the form of many nested menus at different depths, so you just have to select the desired item and press enter. Everything your heart desires is available in this form: telnet sessions, ftp sessions, e-mail, etc. and so on. Also included in this shell are interfaces with such servers, with which it is simply impossible to communicate manually due to their machine-oriented protocol.
Instant Messaging and Messenger Services IRC (Internet Relay Chat or Chat) is the first online communication tool that provides a large selection of channels (topics) for discussions with like-minded people. Chat is a real-time text dialogue. IMS (Instant Messaging Service) is one of the technologies that provides communications on the Internet. In the instant messaging service, in addition to text messages, you can send audio signals, pictures, videos, files.
The most popular instant messengers ICQ (I Seek You - I'm Looking For You) is a popular program (the most common Internet pager) for real-time communication. Skype is the world's most widely used closed protocol messenger. Provides the ability to call landlines and mobile phones, receive calls. The "Video Call" function allows you to talk and share full-screen video from Webcams installed by users. Miranda IM is an open-source multi-protocol instant messaging messenger for working on the Internet or a local network.
CONCLUSION Until quite recently, the Internet seemed to be something strange, mysterious and inaccessible. Now the situation has changed - you can easily access the Global Network from almost any computer, phone and even TV, there are also models that have a browser and can show you a movie online or help you chat via Skype ... According to the latest statistics, more than 2, 5 billion people use the Internet every day. If the total population of the Earth is 8 billion, then approximately 30% visit the Internet daily. In Russia, in 2014, the number of Internet users increased by 2.5 million people: today, 62% of the country's population use the network.
sources http://page.cherepovets.ru/~alko-service/pages/network.html http://www.lessons-tva.info/edu/telecom-glob/glob.html http://info-tehnologii. ru/Komp_seti/slugba_internet/index.html http://eco.sutd.ru/Study/Informat/W98/Net.html https://ru.wikipedia.org/wiki/Usenet www.rusadvice.org https:// en.wikipedia.org/wiki/DNS http://citforum.ru/internet/klimenko/glava_4.shtml http://www.lessons-tva.info/edu/trainbus/1_2.html
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Purpose: To get acquainted with the Internet. And find out the level of its distribution in our school.
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Introduction. What are local networks and global networks? Local area network - a communication system consisting of several computers interconnected by means of cables (telephone lines, radio channels). There is one computer in the network, which is the main one and is called the server, and the rest of the computers are called local.
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What is a server? Server - a special control computer designed to: 1. store data for the entire network. 2. connection of peripheral devices; 3. centralized management of the entire network; 4. determination of message transmission routes;
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Principles of operation of the global network Local computer networks can be combined with each other, even if there are very large distances between them. When two or more networks are interconnected, an interconnection occurs and a global computer network is formed. The global network is a complex structure based on three main principles: First, the presence of a single center in charge of coordinating activities and developing the network; The second is the use of a routing system that allows a message to move along a chain of network nodes without additional human intervention; The third is the use of a single standard addressing, which makes the network "transparent" for external networks, and the latter are accessible to any subscriber point of the system.
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Types of global networks. Varieties of global networks: 1. Commercial - all services are paid. The fee is determined by the user's work time in the network and the amount of information "pumped" by him over the network (KBytes). Tariffs are determined by the type of service. A fee is charged separately for registering a user and connecting him to the network. (Russia - RelCom) 2. Non-commercial - all services are free.
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Internet. Organization of the Internet When two networks are connected, an interconnection occurs, which in English is called the internet. The Internet is a global network that unites many local, regional and corporate networks and includes tens of millions of computers. The Internet has a unique feature. The Internet acts as a self-organizing, self-healing and self-developing structure, which resembles a living organism.
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Internet. Organization of the Internet The only organization that somehow influences the operation of the World Wide Web is the Internet Information Center (InterNIC). It deals with issuing addresses to the Network servers. In order for messages from one Internet participant to be accurately delivered to another, each server must have its own unique address. The InterNIC Center issues addresses and makes sure that they are not repeated.
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Addressing the Internet There are two ways to address the Internet: 1. Using an IP address Each computer connected to the Internet has its own unique physical 32-bit (binary) IP address. The IP addressing system takes into account the structure of the Internet, i.e. that the Internet is a network of networks, not a collection of individual computers. An IP address consists of four decimal numbers, each ranging from 0 to 255. These numbers are written with a dot. For example: 193.126.7.9; 128.29.15.124
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Internet addressing To provide maximum flexibility in the process of determining IP addresses, depending on the number of computers on the network, addresses are divided into three classes A, B, C. The first bits of the address are allocated to identify the class, and the rest are divided into the network address and the computer address . Class. network address. computer address & class A addresses - a number from 0 to 127; & class B addresses - a number from 128 to 191; & class C addresses - a number from 192 to 223. It is enough to simply determine by the first number the computer's IP address, whether it belongs to a network of one class or another:
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Internet Addressing 2. With the help of DNS (Domain Name System) Computers can easily find each other by numeric IP address, however, it is not easy for a human to remember the numeric address, and the Domain Name System (DNS - Domain Name System) has been introduced for convenience. The Domain Name System maps each computer's numeric IP address to a unique domain name. Domain addresses are assigned in the Internet Network Information Center. A domain name usually consists of two to four words called domains. The rightmost group of letters denotes the top-level domain. Top-level domains are of two types: geographical (two-letter - indicates the country in which the host is located, and administrative (three-letter) - indicates the type or profile of the organization that owns the Internet server.
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Internet Addressing Administrative Geographic Commercial - Com England - Uk Educational - Edu Brazil - Br Government - Gov Germany - De International - Int Canada - Ca Military - Mil China - Cn Computer Network - Net Russia - Ru Non-Commercial - Org USA - Us
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Services provided by the Internet The Internet provides its users with a variety of services and opportunities (services). Let's list the main ones. Email (e-mail). Teleconferencing systems (USENET). Information(WWW,GOPHER). File Transfer(FTP).
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E-mail-Em@il Used to send text messages within the Internet, as well as between other e-mail networks. Modern mail programs allow you to attach sound and graphic files, as well as binary program files, to the text of a letter. When using e-mail, each subscriber is assigned a unique postal address, the format of which is: @ Example: school mailbox address - [email protected]
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USENET Teleconferencing System (from Users Network) The teleconferencing system organizes group discussions on various topics. Each teleconference contains a number of discussions on specific topics. Teleconferences are divided into several groups: news-questions concerning the teleconferencing system; comp-computers and software; rec-entertainment, hobbies and arts; sci-research activities and applications; soc-social issues; talk-debate on various controversial issues; misc-everything else.
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World Wide Web World Wide Web (WWW) is a hypertext information system for searching and accessing Internet resources. Hypertext is an information structure that allows you to establish semantic links between text elements on a computer screen in such a way that you can easily navigate from one element to another.
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World Wide Web The WWW system is built on a special data transfer protocol called the Hyper Text Transfer Protocol (HTTP). All contents of the WWW system consist of WEB pages. WEB - pages - hypertext documents of the World Wide Web system. They are created using the HTML Hypertext Markup Language.
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How does the HTML @MAIL.RU page structure look like: mail, news, work, newsletters, entertainment. Mail @MAIL.RU - free mail #1 ... But it's just a header!!!
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World Wide Web The HTML language is very difficult, and in order to understand what it means, programs have been created that translate this language into a form accessible to humans. These programs are called browsers. Browsers (eng. browse - leaf through, view) - programs with which the user organizes a dialogue with the WWW system: browses pages, interacts with WWW servers and other resources on the Internet. There are hundreds of browser programs. The most popular browsers are Netscape Navigator and Microsoft Internet Explorer. The Internet user often has a need to download the information he needs. In this he is helped by a browser that has such an ability. This property is called "FTP mode"
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