What is XHTML?

XHTML is the 'markup' language used to create the basic structure of a web page - page divisions, headings, lists, tables, paragraphs and the like. This markup tells your browser what to show you when it reads (or in technical terms, 'parses') the code for the web page you want to look at. If you right-click on your browser window now and choose 'view page source' you'll see the markup that's used to create this page.

In the past, the forerunner to XHTML, which is still used extensively today, HTML was used to both structure and style a web page - font and background colours, font styles and sizes, italics, page justification, etc.

Nowadays this is considered bad practice and XHTML coders try to avoid using much, if any, styling commands in their code. Instead, they separate the structure of the code from its styling by using 'cascading style sheets'. This helps to avoid web designers producing messy and inaccurate markup and helps make sure that they produce standards-compatible pages.

Used on its own, XHTML is only really capable of producing static web sites, but it can easily integrate other, more powerful technologies such as PHP and MySQL, that enable dynamic web sites to be created around the basic XHTML code used on a web page.