XHTML(Extensible HyperText Markup Language)

The Extensible HyperText Markup Language, or XHTML, is a markup language that has the same depth of expression as HTML(HTML, an initialism of Hypertext Markup Language, is the predominant markup language for web pages. It provides a means to describe the structure of text-based information in a document — by denoting certain text as headings, paragraphs, lists, and so on — and to supplement that text with interactive forms, embedded images, and other objects. HTML is written in the form of labels (known as tags), surrounded by angle brackets. HTML can also describe, to some degree, the appearance and semantics of a document, and can include embedded scripting language code which can affect the behavior of web browsers and other HTML processors.
HTML is also often used to refer to content of the MIME type text/html or even more broadly as a generic term for HTML whether in its XML-descended form (such as XHTML 1.0 and later) or its form descended directly from (such as HTML 4.01 and earlier) SGML)., but also conforms to XML syntax.
Whereas HTML is an application of Standard Generalized Markup Language (SGML), a very flexible markup language, XHTML is an application of XML, a more restrictive subset of SGML. Because they need to be well-formed, true XHTML documents allow for automated processing to be performed using standard XML tools—unlike HTML, which requires a relatively complex, lenient, and generally custom parser. XHTML can be thought of as the intersection of HTML and XML in many respects, since it is a reformulation of HTML in XML. XHTML 1.0 became a World Wide Web Consortium (W3C) Recommendation on January 26, 2000. XHTML 1.1 became a W3C recommendation on May 31, 2001.XHTML is the successor to HTML. As such, many consider XHTML as the current or latest version of HTML [attribution needed]. However, XHTML is a separate recommendation; the W3C continues to recommend the use of XHTML 1.1, XHTML 1.0, and HTML 4.01 for web publishing, and HTML 5 is currently being actively developed.