Definition: HTML

(HyperText Markup Language) The standard document format for Web pages, defined by the Internet Engineering Task Force (IETF). Every Web page contains HTML tags (codes) embedded in the text that define the page layout, fonts and hypertext links. The link contains the URL (address) of another Web page on that same server or any server worldwide, hence "World Wide" Web. The HTML tags also define the graphic elements on the page, each of which is a separate file on a local or remote server. See hypertext.

Since its inception by Tim Berners-Lee in the early 1990s, new versions of HTML have added features such as interactive forms, blinking text, custom backgrounds and tables of contents. To keep current, vendors have to update their Web browsers to accommodate the new tags; however, each new HTML version is backward compatible (mostly) with older versions.

HTML "Is Not" a Programming Language
HTML was created as a markup language (the ML in HTML) to define how a Web page is formatted on screen. Although there are commands that accept user input and send it to the Web server, there is no "if this-do that" in HTML like there is in every programming language. In order to make Web pages behave like applications, JavaScript and PHP programming code are embedded within the HTML. There may be considerable processing at the server side as well. See JavaScript, PHP and Cascading Style Sheets.

HTML5 "Is" a Programming Language
Because version 5 of HTML formalized the use of JavaScript programming, HTML5 is considered a programming language; technically a Web application development language. Among other enhancements, HTML5 added support for audio and video, which otherwise required auxiliary software such as a media player and Flash (see HTML5). See HTML tag, XML, XHTML and SGML.

World Wide Web Linking

Web pages are accessed by their Web address, which is known as a "uniform resource locator" (URL). A website's home page is an HTML document, which contains links to other HTML documents that can be stored on the same server or on a Web server anywhere in the world.

Web Server Fundamentals

Web browsers communicate with Web servers via the TCP/IP protocol. The browser sends HTTP requests to the server, which responds with HTML pages and possibly additional programs in the form of ActiveX controls or Java applets. See HTTP.