XHTML Coding, is a markup language that has the same possibilities as HTML, but it uses a stricter syntax. The changes from HTML to XHTML are minor and basically raise the HTML coding to the XML standards.

The main areas that this covers are:
- The document must be well formed, all elements must have closing Tags
- XML tags are case sensitive, therefore within XHTML all tag names must be in lowercase
- All attribute values must be in quotes