Hypertext Markup Language html. Hypertext Markup Language
Introduction
§ 1. General information about the hypertext markup language (HTML)
§ 2. The structure of the HTML document
§ 3. Design elements of Web pages
§ 4. Practical application of the hypertext markup language HTLM
Conclusion
Literature
Introduction
The paper deals with the hypertext markup language HTML (Hypertext Markup Language); the first specification of this universal and generally available markup language - HTML - was approved in 1991. HTML has become the standard and at the same time the "root" for all developed Web pages.
The relevance of the topic of the work is determined by the fact that today HTML remains the most universal, even irreplaceable means of hypertext markup, and, consequently, publication on the Internet. Writing Web pages in HTML does not require interpreting the source code into binary code.
Today's Web pages are no longer just HTML. It is harmoniously complemented by dynamic HTML tools: script languages JavaScript and / or VBScript, cascading style sheets (CSS), sometimes Java applets are present. In fact, you can display for a modern Web page: Web page = HTML + DHTML (JavaScript / VBScript, CSS, Java applets) + CGI That is, any page must have an HTML layout - the location of text design elements and the necessary scripts - as an extension of HTML in the field of location and description of properties of various objects. CGI scripts can play a primary role by shaping an entire page, filling it with necessary, updated data, or a secondary role by being included in it.
The purpose of the work is to provide a general description of the hypertext markup language HTML. In accordance with the set goal, the tasks of the work are formulated as follows:
1.Overview of the main features of HTML
2. analysis of the practical application of HTML (on the example of training programs).
§ 1. General information about the hypertext markup language (HTML)
Hypertext is a text with embedded words (commands) of markup that refer to other places in this text, other documents, pictures, etc. While reading such a text (in the corresponding program that processes it and performs the corresponding links or actions), you see words highlighted (highlighted) in the text. If you run over them with the cursor and press a key or the button (eye) of the mouse, then what this word referred to, for example, another paragraph of the same chapter of the same text, will be highlighted. In the WWW, using keywords, you can get into a completely different text from another document, enter some program, perform some action, etc. On the Internet, in the context of WWW, you can access anything, telnet, e-mail, ftp, Gopher, WAIS, Archie, USENET News, etc. In the WWW, you can refer to data on other machines anywhere in the network, then when you activate this link, this data will be automatically transferred to the source machine and you will see text, data, a picture on the screen, and if you put the idea of multimedia into practice, you will hear the sound. music, speech. It is a bit like Gopher, but in fact it is fundamentally different and new. Gopher has a rigid menu structure that you move around as you please. This structure does not depend on what you are doing, what document you are using, etc. In the WWW, you move through a document, which can have any hypertext structure. You can freely organize your menu structures in hypertext. With a hypertext editor, you can create any structure of the working environment, including documentation, files, data, pictures, software, etc., and it will not be new software, but just hypertext.
Modern programs for developing Web-servers, such as MS FrontPage or Web Pen for Windows, enable even a beginner to easily create ready-made pages without any study of textbooks. At the same time, a specialist in creating Web sites, called a Web-master, takes ready-made files (texts, tables, graphics, databases, sound, animation, videos, programs) and uses buttons and menu commands to decorate the pages of the site. Such programs, executing commands of the instrumental and operational menus, form the hypertext of the WWW-server.
The original text, table and graphic and other objects are included in the Web-site by means of tags (tag = tag, label). A tag is a sequence of characters that specifies
). the position of the object on the site page,
). the appearance of the object, or
A tag is also called a control marker, a flag. Web Pen programs place the tags themselves, so the user of such programs may not know the hypertext markup language (HTML = HyperText Markup Language).
Knowledge of HTML is essential for five reasons.
First, the Web-master analyzes the sites of competing firms and simply successful instances of WWW-servers. Such analysis, necessary to improve your site, is impossible without knowledge of the hypertext markup language.
Second, improving your Web server without completely reworking it (which is time-consuming and expensive) can be conveniently done by manually inserting and removing objects and tags.
Third, HTML is constantly evolving, so programs like MS FrontPage are constantly lagging behind the latest features of the language.
Fourthly, one should not forget about the rather high cost of such programs.
Finally, fifthly, having spent money on purchasing the program, you still need to spend time on mastering it.
Using HTML, the Webmaster defines the structure of the hypertext document and the appearance of each page. HTML specifies the syntax for the tags that the viewer uses to display document content: text, images, tables, and other types of data. The tags themselves are not displayed by the viewer.
HTML implements support for the mechanism of special hypertext links that link this document with other documents. The latter can be located:
) on this site, that is, in a folder containing all htm files, graphics, sound, animation, videos, programs;
) outside the site in others in folders on this computer;
) on the World Wide Web, that is, on other Web servers;
) on the Internet on other types of servers (FTP, Gopher).
The use of the mechanism of hypertext links creates a global unified information space from which employees of a trading company receive the information they need. The HTML standard, like all other standards related to the Web, is developed under the auspices of the World Wide Web Consortium (W3C). Standards specifications and draft new proposals can be found at # "578258.files / image001.gif"> in the taskbar.
Create a new window of the MS Word word processor using the command of the operating menu (Window, New Window) or by clicking the button of the “Standard” tool menu.
Use the command of the operating menu (Window, Arrange all) to place two windows on the display at once: with a manual and a new one. The cursor should be in a new window. Use the MS Word operating menu command (Insert, Picture ...) to open the "Insert Picture" dialog panel.
Click the file 1stplace.wmf from the list of wmf files on the left side of the dialog box. Consider the picture that appears on the right side of the dialog box.
Repeating the steps specified in paragraph 6, view several figures. Select your favorite multi-colored picture by clicking on the OK button in the lower left part of the dialog box. This figure will appear in a new MS Word window.
Position the mouse pointer on the picture and click the left mouse button. Copy the picture to the clipboard using the command of the operating menu (Edit, Copy) or by clicking the button of the tool menu “Standard”.
Close the window with the picture using the keyboard command. Maximize the size of the window with the manual by clicking the button for maximizing the size of this window.
Go to the window of the paint editor by clicking on the button 
on the taskbar.
With the LView Pro editor, read the bmp file created with Paint and save it as a gif file, after understanding and following the steps below.
Launch File Explorer using the Start button on the taskbar:
START => PROGRAMS => EXPLORER
On drive D: open the LWPRO folder and start the LView Pro editor by double-clicking the file name Lviewpro.exe.
Read a bmp file created with Paint using the LView Pro menu command (File, Open).
Colors in HTML documents can be specified in two ways - by specifying a color code or by specifying a color name in English. In the first method, the color code is written in the form of a hexadecimal number containing six digits: the first two digits set the intensity of the red color, the second - green, the third - blue. The second method uses the following color names: black (black), maroon (dark red), green (green), olive (olive), navy (blue), purple (purple), teal (greenish blue), gray (gray ), silver, red, lime, yellow, blue, fuchsia, aqua and white.
Let's create a document containing a table, the cells of which are colored in different colors. Set the background of the document to black. We will type (or edit) the document with Notepad and write it to the working folder in the colortab1.htm file.
Look at the result with MS Internet Explorer. This result is achieved by applying new attributes and tags. BGCOLOR attribute sets background color in tags
and . It can also be used in tags andmeans a paragraph. In this case, the entire paragraph is aligned to the center of the window (the ALIGN attribute with the CENTER value). The ALIGN attribute can also be LEFT and RIGHT. The paragraph ends with a tag
and after the end of the paragraph, the effect of its attributes ceases.Create a font1.htm document in your working directory, include the text of the above example in its body and see the result. You can speed up the task by copying this example into text generated by Notepad. To do this, select an example in the manual by dragging the mouse pointer (while holding down its left key) along the selection bar to the left of the three lines of the example. Using the colortab1.htm document as an example, create a table3.htm document in the working folder containing a table with the heading "Cell Coordinates" and with 16 cells (4 rows by 4 cells), in which the coordinates of these cells are written according to the C1K1 principle (where C - line, K - column with corresponding numbers). The background of the document should be blue-green, the background of the header line should be white, and the text of the header line should be yellow. Text in table cells should be black on a gray background. Table cells must have borders.
§ 4. Practical application of the hypertext markup language HTLM
The basic principle of the formation of an interactive learning environment for all learning concepts, as shown by practical experience, is the hypertext principle of structuring and presenting information. The theory of hypertext developed in the literature, as well as the existing experience in creating hypertext structures, allow us to outline a number of its essential, structurally significant conceptual features. Let us recall the history of the formation of this phenomenon. Initially, hypertext technologies attracted the attention of teachers as a means of integrating textual information and information presented in other modalities - multimedia (sound, video, animation, etc.). Then the authors - developers of computer training programs discovered hypertext as a means of modeling cognitive processes and thus as a new means of managing these processes. It is symptomatic that the very idea of hypertext (albeit without the introduction of this particular term) was for the first time, as stated in all Western textbooks on the history of this concept and as it is now accepted in the Internet information community, is set out in an article by Vannevar Bush, entitled as follows: “As we may think "; It is from this work that the countdown of the era of hypertext begins as a certain special phenomenon in information theory, linguistics and cognitive psychology, as well as in the field of a new type of artistic word (hypertext fiction).
Currently, the term "hypertext" is applied to various objects: 1) this is the name of a special method of building information systems that provides direct access to data while maintaining logical connections between them; 2) it is a specific system for presenting text and multimedia information in the form of a network of interconnected text and other files; 3) it is a special universal interface, the distinctive features of which are its interactivity and extraordinary friendliness towards the user. The development of hypertext systems for educational purposes began abroad in the 80s, similar work in Russia was until recently at the pilot stage. In 2004, we have seen an exponential growth in the number of hypertext systems offered for distance learning, which is in line with global trends in this area.
Educational materials prepared on the basis of multimedia hypertext technologies have a number of obvious advantages both for the teacher providing, directing and controlling the learning process, and for the student: first of all, these are fundamentally new opportunities for the presentation of educational material associated with the use of visual and auditory clarity. It should also be noted that the very hypertext structuredness of the educational material has its own didactic meaning, since it is a much more flexible form of information presentation, which makes it possible to take into account the individual needs of the student to the maximum extent. In fact, each call to an automated training course, the basis of which is a database made in a hypertext format, is a process of creating your own educational text that most adequately corresponds to a given urgent task, as a result of which the learning process acquires a creative aspect. Establishing logical connections of information blocks, building information, following his own logic of its comprehension, the student essentially becomes a co-author, and, perhaps, this becomes the most attractive aspect of using such courses in the learning process. However, it must be emphasized that the key problem in such a system is the problem of organizing "navigation", a free or imposed by the author-developer strategy for studying this information field, which, moreover, must solve the didactic problems themselves. In studies on the theory of hypertext, the issues of organizing the "reading" of hypertext information are considered in conjunction with a formal analysis of the structure of the hypertext field, the capabilities of technical means of "navigation" control, as well as the peculiarities of a person's cognitive strategic preferences (we emphasize again that the latter is still the least studied area ). The models that underlie automated search systems and automatic query processing systems often serve as fairly well-developed formalized strategic models.
a) at the first, highest level, the genre of the shortest possible annotations is used for all basic terminological concepts,
b) at the next level, a substantive interpretation of certain concepts is given,
In the prepared educational computer materials, the optimal number of permissible links per paragraph of text (no more than 1 - 2 links), as well as the recommended amount of text information: when displayed on a computer screen, it should take no more than 1.5 or 2- x screens. The permissible and recommended hierarchical depth of connections was established in accordance with the data of the theory of information perception and cognitive linguistics. It was assumed that, depending on the individual cognitive styles of assimilating information, it can range from 2 to 5 steps. In a number of psychological and psycholinguistic works devoted to the theory of hypertext, attempts have been made to identify basic strategies that were preferable for different groups of people; The obtained data allow us to outline three main types of behavior in the hypertext space, it is customary in the English-speaking tradition to call them depth-first navigation, breadth-first navigation and two variants of an intermediate strategy (random navigation), combining in certain proportions the first two approaches). However, it should be noted that all researchers, without exception, emphasize the need for additional experiments in this direction to establish the degree of reliability of the data obtained. Undoubtedly, this issue requires further, deeper study, therefore, in this work, we were guided mainly by intuitive ideas about the optimal structure of connections, which were dictated by the specifics of the material underlying the hypertext.
Proof testing and oral questioning are some of the most widely used and well-developed means of testing knowledge in higher education. The classic test is a sequence of fairly simple questions. Each question has a simple answer that can be formally checked and evaluated as correct, incorrect, or partially correct (for example, incomplete). Questions are usually classified into types according to the type of expected response. Classic question types are divided into [yes / no] questions, [many / one answer] (MV / OO) questions, [many / many answers] (MV / ML) questions, and open-ended questions with text or numeric the answer. More advanced question types include matching questions, sequence questions, pointing questions (the answer is one or more areas in the picture), and graphical questions (the answer is a simple graph). In addition, each subject area may have some specific types of questions.
The support options at the build stage usually depend on the technology used to store the individual issue on the system. Currently, we know of two different ways of storing a question: in the presentation format and in the internal format. In the context of Web-based learning, storing a question in a presentation format means storing it as part of the HTML code (usually in the form of an HTML form). These questions can also be called static questions. They are black boxes for the WBE system. The system can present static questions only "as is" (in the form in which they were created). Creating questions of this type is often not supported by the WBE system, as it can be done in any HTML editor.
The type of interactive technology used to generate learner responses is one of the most important characteristics of WBE systems. It defines all the functionality at the stage of issuing questions, and also influences the stages of creating and evaluating questions. Currently, five technologies are distinguished: HTML links, HTML / CGI forms, scripting languages, plag-in and Java. Links are the simplest interaction technology that implements a set of possible responses as a list of HTLM links. Each link is linked to a specific feedback page. When using this approach, two problems arise: the complexity of creating questions (the logic of the question should be rigidly built into the hypertext of the course) and support for only two types of questions: [yes / no] and [MV / OO]. This technology was used primarily in the early days of Web-based learning, when more advanced interoperability technologies such as CGI, JavaScript, or Java were not yet developed.
The most popular Web testing technology currently used by numerous commercial and university systems is a combination of HTML forms and CGI scripts. HTML forms are extremely handy for presenting basic types of questions. Questions like [yes / no] and [MV / OO] are represented by icon sets, selection lists, pop-up menus. [MV / MO] questions are represented by multiple choice lists or radio button sets. Open-ended questions are implemented as edit fields. More advanced questions, such as matching or correct sequence questions, can also be implemented using forms. In addition, hidden fields can be used to store additional information about the test that the CGI script might need. Significant benefits from using server-side technology (which includes form / CGI technology) and similar server-side map technology arise in the implementation of graphical pointing questions.
Conclusion
Based on the results of solving the problems of the work, the following results were obtained:
HTML is an ordinary, text-like file in which what we usually see on pages is interspersed with code that is invisible for viewing from a browser. This invisible code is the HTML markup language.
HTML is not a programming language - it only serves to mark up the page, to give a certain look to this or that element, be it a table, text or pictures.
This is done by assigning each element its own parameters, which are recognized by the browser. These parameters can be set both for one and for a group or type of elements. The type of elements can be as follows: tables, cells, links, text, etc. That is, something that can be called one term. Individual properties can be assigned to selected elements as well. The main reason for the proliferation of Web servers in recent years is that they are relatively easy to install and are becoming an increasingly large business tool. The second reason is the availability of more and better HTML editors and text converters to enable the creation of new Web pages.
With regard to the scope of application, the following can be said. The future of the Web is also related to the increasing speed of data transmission on the Internet, as the Web is inextricably linked with the Internet.
The problem of incompatibility between browsers and Web servers is likely to remain, as Netscape Communications has extended HTML somewhat, which prevents all browsers from displaying documents written in the new HTML format.
Literature
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Kirmayer M. Information technology. SPb .: Peter, 2003 - 443 p.
Matthews J. Web Server. SPb .: Symbol, 1998 - 356 p.
Olifer V.G., Olifer N.A. Computer networks. SPb .: Peter, 2005 - 864 p.
Olifer V.G., Olifer N.A. Network operating systems. SPb .: Peter, 2003 - 539 p.
WWW technology
The World Wide Web (WWW) service is the most popular service on the Internet. WWW is a unified information space consisting of hundreds of millions of interconnected electronic documents stored on Web servers. The individual documents that make up the Web space are called Web pages. Groups of thematically connected Web pages are called Web sites (Web site). A single physical Web server can contain many Web sites, each of which is assigned a separate directory on the server hard disk.
Web pages differ from ordinary text documents in that they are designed without reference to a specific medium. For example, the design of a Word document printed on paper is tied to the parameters of the printed sheet, which has a certain height, width and size of margins. Electronic Web-documents are intended for viewing on a PC screen, and it is not known in advance on which one. Therefore, Web documents cannot be rigidly formatted. The design is performed during their playback on the client's PC and it is performed in accordance with the settings of the program performing the viewing (browser). The browser displays the document in accordance with the commands that are written in the text of the Web document. Commands can be written either directly by the author of the document, or implemented by automatic means of preparing Web-documents.
Such commands are called tags. Tags are enclosed in brackets<>... Most tags are used in pairs: an opening tag and an end tag.
In addition to the keyword, complex tags have additional attributes and parameters. The rules for writing tags are contained in the specification of a special hypertext markup language - HTML (Hyper Text Markup Language). That is, a Web document is a plain text document tagged with HTML tags.
The most important feature of Web documents is hypertext links. A hyperlink can be set to any piece of text. A paired tag is used to create a hyperlink ... This tag contains the required HREF attribute, which specifies the URL of the document to which the link points.
The address can be specified in absolute and relative form. An absolute address begins with a protocol and a Web site address. This entry is used when you want to direct a visitor to another Web site and is treated as an external link. When using a relative address in the link, only the relative search path for the document is specified. This assumes the use of the same protocol and the same Web site, and treats the link as internal. An internal link remains functional if the address of the Web site changes as a whole (for example, to a different server). The full hyperlink format includes the ability to link to a specific location within the page. But this can only be done for self-developed pages. For this, the place where the link is placed is marked with a special anchor element. The anchor is set using a paired tag with the required NAME attribute. The value of this attribute is an arbitrary sequence of Latin letters and numbers - the name of the anchor. To link to an anchor, its name appears at the end of the URL after the # symbol.
The browser will search for a document on this server in the current folder
The browser will go to the site http://www.midi.ru.
The aggregate of a huge number of hypertext documents stored on WWW servers forms a kind of space for hyper-documents, between which it is possible to move. Arbitrary movement between documents is called Web-surfing, and purposeful (performed in order to find the necessary information) - Web-navigation.
Hypertext communication between the vast number of documents stored on physical Internet servers is the basis for the existence of the logical WWW space.
Consider the hardware and software that collectively make up the Web.
· Clients and Servers. A web server is a computer connected to the Internet that runs a special program, also called a web server. The tasks of this program include storing, searching and distributing certain files on the Web. A web client is a browser that requests files from the web. When a client computer wants to access one of the files, the request is routed to the web server. The server searches for the specified file and sends it to the client computer that sent the request. The thousands of computers that make up the Web are a wide variety of hardware and software combinations. When a client computer requests a file, it knows practically nothing about the features of the server where the required file is stored, or about other computers that will transfer the file to each other on its way from the server to the client. For such a system to work, it must use a set of languages and protocols that are independent of hardware or operating systems.
· URL and data transfer protocols. If fragments of a document are scattered all over the world, and you want to present it to the user as a single, consistent document style, you will need a very good address system. Every file on the Internet has an address called a URL (Uniform Resource Locator). For example, the URL of the website of the European Federation football - http://ru.uefa.com.
The first part of the URL defines the method by which the computer accesses the file, that is, the communication protocol. Most web pages are accessed using the HTTP (Hypertext Transfer Protocol). This is why the web address is usually specified using the letters "http", and browsers automatically insert these letters before the web address entered by the user. Often a part the http: // addresses are omitted at the beginning of the URL.
The next part of the address is the hostname of the web server. The domain name system will route your request to the web server wherever it is.
Some URLs contain information followed by the hostname of the web server. This data exactly identifies the file you want to view and the directory where it is stored. If no directory and file names are specified, the default web page for that web server is displayed.
· Html(Hypertext Markup Language - hypertext markup language) is the universal language of the Web. It is used to lay out pages on which information posted on the Web can be reproduced: textual, graphic, as well as audio and video information.
· Java and JavaScript. The Java language is designed for sending small applications (called applets or Java applications) over the Web. And JavaScript extends the capabilities of HTML to embed small programs (or scripts) into web pages. The main purpose of applets and scripts is to increase the interactivity of web pages — instead of interacting with a remote web server, you work with an applet and a script that runs on your computer.
There are also Java applets and JavaScript for building animations, which are sent by a web server over the network to be executed on the user's computer; they avoid the transmission of animation frames over the Internet. The described processes usually occur unnoticed by the user.
· VBScript and ActiveX Controls. VBScript and ActiveX controls are standard tools supported by Internet Explorer.
VBScript is a simplified version of the Visual Basic language developed by Microsoft. It can be used to create scripts that make web pages dynamic. Thus, VBScript is similar to JavaScript in its capabilities.
ActiveX controls, like Java applets, are used to embed executable programs in web pages. When Internet Explorer comes across a web page that uses ActiveX controls, it checks to see if the specific control is installed on your computer, and if not, installs it.
· XML and other extended languages of the Web. XML (Extensible Markup Language) is a very powerful language that should replace HTML as the application development language for the Web. Unlike HTML, XML does not contain any instructions on how the data described in the XML document should be displayed. The way they are displayed is determined by the style description language, which plays about the same role for XML as cascading style sheets for HTML. The W3C works with two style sheet specifications: XSL (Extensible Style Language) and CSS (Cascading Style Sheets). Another fundamental difference between XML and HTML is that it can contain any tags that the creators of the XML dictionary want to use.
A more advanced version of HTML is DHTML (Dynamic HTML - Dynamic HTML), which includes three components - HTML, JavaScript and CSS.
· Graphic objects. Pictures, drawings, maps, diagrams, and other graphics presented on the Web can be in many formats. The most common formats for displaying graphic information are JPEG and GIF.
· Audio and video files. The web provides many audio and video files that are played through the browser's integrated plug-ins. There are two ways to transfer such data: the browser can either download it as a whole file (then the entire amount of information will have to be played, which will take a lot of time, since audio files are large, and video files are simply huge), or take only that part of the file, which you want to play at the moment. The second method is called streaming audio or streaming video.
HyperText Markup Language(HTML) - Hypertext Markup Language - designed for writing hypertext documents published on the World Wide Web.
Hypertext Document Is a text file that has special labels called tags, which are subsequently recognized by the browser and used by it to display the contents of the file on the computer screen. With these labels, you can highlight the titles of the document, change the color, size and style of letters, insert graphics and tables. But the main advantage of hypertext over regular text is the ability to add to the content of the document hyperlinks- special constructs of the HTML language, which allow you to switch to viewing another document with a click of the mouse.
There are two ways to create hypertext documents. You can use one of the WYSIWYG HTML editors (for example, Microsoft FrontPage, or others), which do not require special knowledge about the internal structure of the document being created. This method allows you to create documents for the WWW without knowing the HTML language. HTML editors automate the creation of hypertext documents, eliminate routine work. However, their capabilities are limited, they greatly increase the size of the resulting file and the result obtained with their help does not always meet the developer's expectations. But, of course, this method is indispensable for beginners in the preparation of hypertext documents.
An alternative is to create and mark up a document using a regular text editor (NotePad). This method manually inserts HTML commands into the text. By creating documents this way, you know exactly what you are doing.
As noted, an HTML document contains symbolic information. One part of it is the text itself, that is, the data that makes up the content of the document. Another - tags(markup tags), also called marking flags, - special constructs of the HTML language used to mark up a document and control its display. It is the tags of the HTML language that determine in what form the text will be presented, which of its components will play the role of hypertext links, which graphic or multimedia objects should be included in the document. The graphic and sound information included in the HTML document is stored in separate files. HTML document viewers (browsers) interpret the markup flags and arrange text and graphics on the screen accordingly. For files containing HTML documents, the .htm or .html extensions are accepted.
Uppercase and lowercase letters are not distinguished when writing tags. In most cases, tags are used in pairs. A pair consists of a start tag and an end tag. Opening tag syntax:
<имя_тега [атрибуты]>
Brackets used in syntax descriptions indicate that the element may be missing. The name of the end tag differs from the name of the opening tag only in that it is preceded by a forward slash:
Tag attributes are written in the following format:
name [= "value"]
Quotation marks when specifying an argument value are optional and can be omitted. For some attributes, a value may not be specified. The end tag has no attributes.
Any paired tag begins where the start tag is encountered and ends when the corresponding end tag is encountered. Often, a pair of start and end tags is called container, and the part of the text, bordered by the opening and closing tags, is element.
The sequence of characters that make up the text can consist of spaces, tabs, line feeds, carriage returns, letters, punctuation marks, numbers, and special characters (for example, +, #, $, @), with the exception of the following four characters that have special meanings in HTML:< (меньше), >(greater than), & (ampersand) and "(double quote). If you need to include any of these characters in the text, you should encode it with a special sequence of characters.
Internet Engineering Task Force) posted a draft of the HTML standard proposalHTML document structure
An HTML 4 document has three parts:
- a string containing HTML version information,
- declaring a header / header section (delimited by the HEAD element),
- a body containing the actual document itself.
The body can be contained in BODY or FRAMESET elements. Whitespace characters(spaces, newline characters, tabs and comments) may appear before or after this section.
Hello world!
Document starts with element type document, or doctype. It describes what type of HTML will be used - so that the user's client application can determine how to interpret the document and decide whether it follows the rules it intended to follow in its statement.
After that, you can see the opening tag of the html element. It is a wrapper around the entire document. The closing html tag is the last object in any HTML document.
Inside the html element there is a head element. It contains information about the document (metadata). Inside the head is a title element, which defines the "Simple page" title in the menu bar.
The head element is followed by a body element, which is a wrapper containing the actual content of the page - in this case just a first-level heading element (h1) that contains the text "Hello world!" ...
Items often contain other items. The body of the document will always contain many nested elements.
Sections on a page create the overall structure of a document, and can contain subsections. They can also contain headings, paragraphs, lists, etc. Paragraphs can contain elements that create links to other elements, quotes, highlights, etc.
HTML element syntax
A basic element in HTML consists of two tags around a block of text. There are elements that do not wrap text, and in almost every case, elements can contain subelements (as html contains head and body in the example above).
Items can also have attributes that can modify the behavior of the element and introduce additional value.
The basics Html
In this example, the div element (page section, a way to divide documents into logical blocks) has an added id attribute that is set to masthead... The div element contains an h1 element (the heading of the first or most important level), which in turn contains some text. Some of this text is packed into an element abbr(which is used to define the abbreviation extension), which has a title attribute set to Hypertext Markup Language.
Many attributes in HTML are common to all elements, but some are specific to a given element or elements. They all have the form:
keyword = "value"
The value must be enclosed in single or double quotes (in some situations, quotes may be missing, but this is not very good from the point of view of predictability, understanding).
Attributes and their possible values are mainly determined by the HTML specifications (http://www.w3.org/TR/html401/index/attributes.html), so you cannot create your own attributes. The only real exceptions are the id and class attributes, whose values are entirely intended to add your own meaning and semantics to documents.
An element inside another element is called "descendant" of this item. In the example above abbr is a child of h1, which is in turn a child of a div. Conversely, div is the "ancestor" of the h1 element.
Block level and inline elements
There are two main categories of elements in HTML, which correspond to the types of content and the structure that these elements represent - block level and inline elements.
Block level denotes a higher level of an element, usually giving information about the structure of a document. You can think of block-level elements as starting on a new line, breaking away from what came before. Common block elements are paragraphs, list items, headings and tables.
String elements are contained within block-level structural elements and cover only portions of the document text, not entire areas. An inline element does not cause a new line to appear in the document, since they are elements that appear in a paragraph of text. Common string elements are hypertext links, highlighted words or phrases, and short quotes.
Heading
The head of the HTML document is an optional markup element. Originally, the existence of the title was dictated by the need browser window naming... This was achieved through markup element TITLE:
Another function of the HTML document header is to control the HTTP exchange via markup element META. With the current practice of hosting company Web sites on providers' servers, the administrators of these sites may not be able to manage the server program. In this case, there is only one option left to control the exchange - through the header of the HTML document.
The header of the HTML document is also intended to describe the search image of the document, which is necessary for the indexing of the document by the search engine robots. The META element allows you to store lists of keywords and document descriptions that will be used to compose the search engine index and appear as a description of the document if a link to it is returned during a keyword search.
Basic header tags are HTML markup elements that are most commonly found in the header of an HTML document, i.e. inside markup element HEAD:
- TITLE (title of the document);
- BASE (base URL);
- ISINDEX (search pattern);
- META (meta information);
- LINK (general links);
- STYLE (style descriptors);
- SCRIPT (scripts).
The most commonly used elements are TITLE, SCRIPT, STYLE. The use of the META element indicates that the author is aware of the rules for indexing documents in search engines and the ability to control HTTP data exchange. BASE and ISINDEX are practically not used lately. LINK is specified only when using style sheet descriptors external to this document.
Markup element HEAD contains the head of the HTML document. The markup element is optional. If there is a start tag markup element it is desirable to use the end tag as well markup element... By default, the HEAD element is closed when either the BODY container start tag or the FRAMESET container start tag is encountered.
The header container is used to contain information related to the entire document as a whole.
Markup element TITLE is used to name a document on the World Wide Web. When choosing text for the content of the TITLE container, keep in mind that it is displayed system font because it is the title of the browser window.
The general syntax for the TITLE container is as follows:
The header is not required as a container for the document. It can be omitted. Many search engine robots use the content of the TITLE element to create a search image of a document. Words from TITLE go to the search engine index. For these reasons, the TITLE element is always recommended for use on Site pages.
Markup element BASE is used to determine the base URL for hypertext links of the document, given in incomplete (partial) form. In addition, BASE allows you to define the default document loading target window when you select the hypertext link of the current document. Most often BASE is found on site pages that have "mirrors". For various reasons, some of the documents on the main server are not transferred to the "mirror" server. In this case, the document with the forced base URL will always link to the main server.
The container start tag contains one required HREF attribute, and can contain one optional TARGET attribute. The syntax for a BASE container is generally as follows:
Markup element ISINDEX is used to specify a search pattern and is inherited from earlier versions of HTML. This container is not defined in HTML 4.0.
META markup element
META contains control information that the browser uses to correctly display and process the content of the document body, for example, using the Content-type attribute, you can specify the client-side transcoding of the document.
Other operators can also be specified using META. For example, disable caching of the document. To disable caching, it is enough to insert into the META header - a tag of the form:
In the new version of the HTTP protocol (HTTP 1.1), caching is controlled through the Cache-Control operator. To get the same result as with Pragma, in the head of the HTML document, it is enough to specify:
You can prevent the document from being stored after it has been sent.
HyperTextMarkupLanguage (HTML) - Hypertext Markup Language - designed for writing hypertext documents published in WorldWideWeb.
A hypertext document is a text file that has special labels called tags, which are subsequently recognized by the browser and used by the browser to display the contents of the file on a computer screen.
With these labels, you can highlight the titles of the document, change the color, size and style of letters, insert graphics and tables. But the main advantage of hypertext over regular text is the ability to add hyperlinks to the content of the document - special constructs of the HTML language that allow you to click on another document to view another document.
HTML document structure
The most important of the HTML tags is the tag of the same name. ... It always opens the document, just like the tag must certainly be in its last line. These tags indicate that the lines between them represent a single hypertext document. Without these tags, the browser or other viewer is unable to identify the document format and interpret it correctly.
An HTML document consists of two parts, a head and a body, in the following order:
Document title Body of the documentMost often, the title of the document includes a paired tag
The body of the document is a required element, since it contains all the material of the document. The body of the document is placed between tags
and... Everything that is placed between these tags is interpreted by the browser in accordance with the rules of the HTML language that allow the correct display of the page on the monitor screen.Text in HTML is divided into paragraphs using a tag<р>... It is placed at the beginning of each paragraph, and the viewer encounters it and separates the paragraphs from each other with a blank line. Using an end tagnot necessary.
If you need to "break" the text by wrapping the rest of it on a new line, and without highlighting a new paragraph, use the line break tag
... It causes the viewer to display the characters following it on a new line. Unlike the paragraph tag, the
does not add an empty line. This tag does not have a matching end tag.
HTML supports logical and physical formatting of document content. Logical formatting indicates the purpose of a given piece of text, while physical formatting determines its appearance.
When using logical text formatting, the browser highlights different parts of the text according to the structure of the document. To display the title, one of the title tags is used. Headings in a typical document are categorized into levels. HTML allows you to define six heading levels: h1 (first level heading), h2, h3, h4, h5, and h6. The first level heading is usually larger and heavier than the second level heading. An example of using header tags:
l.l. Section title
Physical formatting tags directly control the appearance of the text on the browser screen, for example, a couple makes the text bold, sets the underline of the text, controls the font of the text.
Tag inserts an image into the document as if it were just one large character. An example of using the tag:
A couple of tags are used to create a hypertext link<а>... ... A piece of text, an image, or any other object located between these tags is displayed in the browser window as a hypertext link. Activation of such an object causes a new document to be loaded into the browser window or to the display of another part of the current Web page. A hypertext link is formed using the expression:
Href here is a required attribute, the value of which is the URL of the requested resource. Quotation marks are optional when specifying the value of the href attribute. If a link is set to a document on another server, then the type of hyperlink is as follows:
<а href = "http://www.school.donetsk.ua/11.jpg">Photo 11-A
Using various tags, you can draw tables, format text, insert images, video-sound files, and more into a document.
Hypertext markup is used to indicate in which part of the screen and how the text should be displayed and how the texts that make up the hypertext database are related to each other. For these purposes, special control characters are introduced into the text. Escaped text is stored in a plain text file in ASCII codes and can be processed by almost any text editor.
The hypertext markup language HTML was proposed by Tim Berners-Lee in 1989. At the time of the creation of HTML, there was a standard for the markup language for printed documents - SGML (Standard Generalized Markup Language), which was taken as the basis of HTML. It was assumed that such a solution would help to use existing software to interpret the new language.
As an element of the hypertext database for HTML, a plain text file was selected, which is stored by means of the file system of the operating environment.
Thus, a hypertext database in the WWW concept is a set of text files written in the HTML language that defines:
Information presentation form (markup);
The structure of links between files (hypertext links). This approach assumes the presence of one more component
technology - language interpreter. In the WWW, the interpreter functions are split between the hypertext database server and the user interface. The server, in addition to accessing documents and processing hypertext links, also carries out preprocessing processing of documents, while the user interface interprets language constructs associated with the presentation of information.
In 1990. there was a zero version of HTML 0.
The first version (HTML 1.0) was aimed at representing the language as such, where the description of its capabilities was rather advisory in nature.
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The second version (HTML 2.0) fixed the practice of using language constructs and became the standard for building the WWW.
The ++ version of HTML ++ introduced new possibilities for presenting scientific information and tables, and improving the layout style of text and images.
The third version (HTML 3.0) streamlined all the innovations and formalized the user interface of the hypertext distributed system.
In 1996. a new version of the language has been released: HTML 3.2, which includes tools for creating tables, Java language constructs, image maps (located on the client machine) and new types of text formatting.
HTML is a text-based language in which formatting instructions, called tags, are embedded in the text of a document.
The process of creating an HTML document consists in including tags inside unformatted text that carries informational load.
HTML tags are sequences of characters that begin with a less-than sign (<) и заканчивающиеся знаком “больше” (>).
Most of the formatting functions in HTML specify logical rather than physical styles. For example, heading tags, which usually indicate larger letter sizes, do not indicate which size to use. The browser (which acts as a client program) chooses a larger text size for headings. This approach allows you to get rid of the platform - a document created on a Macintosh can be used by UNIX or Windows. The downside is that the document looks different on different platforms.
WWW browsers work according to the following rules when parsing HTML sentences:
Spaces and other "invisible" characters are ignored;
All tags can be divided into groups: base tags, formatting tags, structure tags, pointers, etc .;
Formatting tags can be written in lowercase and / or uppercase letters;
Most formatting tags are written in pairs. An opening tag activates this effect, and a closing tag turns it off. A pair of tags is sometimes referred to as a container because the effect they turn on and off appears on the text within them. For example, to indicate that a string should be printed in bold characters, one would write:< B >This line will be printed in bold text
Text inside an end tag is always preceded by a backslash character. Among the basic HTML tags, the exceptions to this rule are:< BASE >(basic information),< BR >(end of line),< HR >(horizontal ruler), and< IMG >(image). These tags exist in a single copy.
Every HTML document has border tags:< HTML >and... This pair of tags encompasses all other tags on the Web page and all of the information content of the document. In fact, they declare that all the contents of the container are HTML code. Tag< HTML >must be on the first line of the file, and the tag- in the latter.
Each HTML document contains the title of the document and its body.
The document title identifies the document. It should go right after the tag< HTML >and start with< HEAD >... The title ends with a tag.
The title of the document must contain the title of the document and its base URL.
The name of the document is located between the tags< TITLE >and... It is used by the browser and web server. The name must not exceed 40 characters. The title of the document should be informative, reflect the content of the document so that it can be identified. The name appears in the title bar of Internet Explorer, in History lists and in Favorites.
The base URL must be fully qualified (absolute) and contain the protocol, Internet address, and filename. It is indicated in the tag< BASE HREF = “базовый_URL”>... All other URLs in the document can be relative to the base one. For example, if the base URL is: http://www.microsoft.com/products/office/word/datasheets.html and you need to specify the URL of the features. html located in the / products / office / excel directory on the same server, you can specify: ../ excel / features. html instead of typing the full URL.
Symbols. ./ indicate that you want to go one directory level up from the base address.
Having a base address makes it easier to transfer a document to another server, because if all other URLs in the document are relative, then only the server name in the base URL needs to be changed during the transfer.
Body of the document contains all the text that carries information and all the HTML tags used to format the text. The body of the document begins immediately after the heading and is delimited by tags< BODY >and.
Example HTML document:
< TITLE >Document's name
< BASE HREF = “базовый_URL” >
Tags used in the body of the document allow you to specify the following elements of text markup:
Beginning of paragraph and end of line
Heading styles
Physical Styles -Logic Styles
Special symbols.
Hypertext links consist of two parts: a pointer and a URL. A pointer is text that the user must click on in order to move somewhere. The URL specifies the address from which the browser will download the document when the user clicks on the pointer.
Text pointers in graphical browsers are usually underlined and highlighted in color. In pure text browsers, they are in bold.
Any text can be used as an index, regardless of its size and formatting features. An index can be composed of multiple letters, words, or even lines of text.
Pointer format:
< A HREF = “ URL ”>index text ,
where is the letter A in the tag< A HREF >stands for anchor and HREF stands for Hypertext REFerence. Everything between tags< A HREF = “ URL ”>andis the index text that is displayed in underline or bold type.
Other formatting codes can be used in conjunction with hypertext pointers. For instance:
< A HREF = “ URL ”> < I > or
< I > < A HREF = “ URL ”>Moving on to a more detailed presentation
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