This is the language computer programmers use to mark up text and media. There are several mark up languages, depending on the use. HTML stands for Hypertext Markup Language and is used for information to be accessed by a Web browser. SGML is Standard Generalized Markup Language, a language for describing markup languages, particularly those used in electronic document exchange, document management, and document publishing. HTML is derived from SGML. XML is also based on SGML and stands for Extensible Markup Language. It is an unlimited, self-defining language that lets you create new commands to suit your needs. HTML, by contrast, is a fixed language by which you can only describe how you want text or graphics to appear structurally.