World Wide Web (WWW) is weaved from Web pages, which are created with the help of so-called language of a marking hypertext HTML (Hypertext Markup Language). Though many speak about programming in this language, HTML at all is not the programming language in traditional understanding. HTML is a language of document marking. By development of the HTML-document the marking of the text document precisely is carried out the same as the editor by means of a red pencil does it. These marks serve for the indication of the form of representation of the information contained in the document.

Special programs of viewing of HTML-documents, which frequently name browsers, serve for interpretation of the files marked by rules of HTML; they're formatted as Web pages and display their contents on the screen of a computer. There is a plenty of the programs - browsers developed by the various companies, however, for today from all variety of programs two programs - leaders - Netscape Communicator and Microsoft Internet Explorer.

Company Netscape Communications Corporation develops program Netscape Navigator. As well as many software products, have number of versions of this program. MS Internet Explorer is developed by Microsoft corporation.

Other browsers considerably lag behind on popularity. Several years ago the browser of company Netscape leading place among browsers, more than two thirds of users applied this program of viewing. Having released the browser, company Microsoft has made huge efforts for a gain of this part of the market. In mass media frequently there were messages on war between browsers for users. Now these two browsers are comparable on popularity. Growth of popularity of browser Microsoft is promoted by inclusion of a browser in structure of operational system Windows 98, however, finally, the choice of a browser remains for the user. Our stats shows however about 90% of users use MS Internet Explorer.

To understand, that itself represents language of a marking, we shall recollect old kind times when many worked with text editors such as WordStar. In them for allocation of any phrase, for example, the semi boldface font, in its beginning and in the end put special marks (/B and/b):

/BThis the text will be shown by a semi boldface font /B

At a conclusion of such text to the printer (about displays still speech does not go, during those far times of them still either was not in general or there were the alphanumeric displays, not allowing to change fonts) symbols/? forced to use a semi boldface font until there will be symbols/b.

HTML works precisely the same way. If there is a necessity to allocate the text on the screen a semi boldface font it can be made similarly:

<B> This text will be shown by a semi boldface font </B>

Symbols <B> include a semi boldface tracing, and symbols </B> switch off it. Such symbols which operate display of the text and thus are not displayed on the screen, in language HTML it is accepted to name tags (from the English word tag - a label, an attribute).

All tags of language HTML are allocated with symbols - terminators (<and>), between which the identifier of a tag (in our example it b), and, probably, its parameters enters the name. Unique exceptions of this rule are tags of the comment with more complex terminators (<! - and->). Names of tags, and also their parameters it is possible to write down on any register.