HyperText Markup Language (HTML) is a markup language designed for creating web pages, that is, information presented on the World Wide Web. Defined as a simple "application" of SGML, which is used by organizations with complex publishing requirements, HTML is now an Internet standard maintained by the World Wide Web Consortium (W3C). The most recent version is HTML 4.01.
HTML generally appears in text files stored on computers connected to the World Wide Web. These files contain information in plain text mixed with markup, that is, instructions for the program on how to display or process the text. Usually HTML is displayed by a web browser, but many email clients also allow sending and reading HTML e-mails.
There are four kinds of markup elements in HTML:
- structural markup that describes the purpose of text (for example,
<h1>Golf</h1> will cause a reader to treat "Golf" as a first-level heading),
- presentational markup that describes the visual appearance of text regardless of its function (for example,
<b>boldface</b> will render boldface text),
- hypertext markup that links parts of the document to other documents (for example,
<a href="http://www.wikipedia.org/">Wikipedia</a> will render the word Wikipedia as a hyperlink to the specified URI), and
- widget elements that create objects (for example, buttons and lists).
As with many Internet standards, the popularity and technological advancement of the World Wide Web grew much faster than standards bodies
could track, so there are some incompatible proprietary versions of HTML still in use, though standards
are improving. But nowadays most features of HTML4 are implemented by the major browsers. HTML4 gives a fairly comprehensive set of formatting options, however most of these have been deprecated
in favor of Cascading Style Sheets
(CSS) or similar, which should be used for formatting, while HTML should be used for describing the structure and the logic of the page only.
Version history of the standard:
There is no HTML 1.0 specification because there were multiple informal HTML standards at the time and so the formal specification was given the version number 2.0 in order to distinguish it from these.
There will no longer be any new versions of HTML. However, HTML lives on in XHTML, which is based on XML.
With the release of HTML 4.0, many elements and attributes relating to presentation (the
bgcolor attribute and
font element, for example) were deprecated in favor of CSS, and entirely removed from the strict "Document Type Definition".