HyperText Markup Language
The HyperText Markup Language, commonly abbreviated as HTML is literally what it says on the tin, a hypertext markup language used to create web pages and user interfaces with. It is a subset of SGML and was introduced in 1991 by Tim Berners-Lee with his Web browser for the NeXT computer system and was initially a tool used by scientists working at CERN.
It uses tags enclosed in angle brackets as for example <body>, the tags usually come in pairs like <rel> and </rel> in which case the first tag, called an opening tag, represents the start of a formatting or feature and the tag with the forward slash, commonly referred to as the closing tag, represents the end of formatting. There are some tags that represent empty elements and therefore are unpaired, for example <img> and some tags can close themselves with a forward slash at the end such as <example />
Here below is an example of a HTML webpage missing only a header
<body> <h1>Main headline goes here</h1> <p>The emphasis (em) tag is used to <em>place emphasis on a portion of text</em>, in most systems and in all browsers this is done by converting the emphasised text to italics, but in some SMGL systems that are mostly oriented towards printed output this may be converted into bold text. Browsers intended for those with vision impairments may also choose to format em differently and tools that convert the HTML page into something else like spoken word may choose or need to make other choices.</p> <h3>Alternatively.....</h3> <p>You may choose to do the <b>emphasising formatting yourself</b> by using either a bold (b) or italics (i) tag <i>in place of the em tag</i> although that is discouraged since em shows intent and may therefore translate correctly between media and languages while the i and b tags are presentational and may not.</p> </body>