Introduction
Hyper-Text Markup Language(HTML) is a language used to describe the format of text in a document. HTML is based originally on a subset of elements found in SGML(Standard Generalized Markup Language). Both SGML and HTML consists of specialized tags, delimited by < and > symbols, which are intermixed with regular text to indicate the formatting or display of that text. SGML is a more complex and complete text description language than is HTML. As HTML was a simplified version of SGML, HTML readers (devices and programs that can perform the formatting specified by the language) were easier to build than they were for SGML. There is a HTML reader in every web browser. You are reading text that uses HTML for formatting and display. Usually it is customary to refer to this text document that contains HTML as a HTML Document.