HTML&XHTML
HTML (Hypertext Markup Language) is a sort of tag language for making web pages. And this language needn’t to be translated or edited. We can execute it by browser. It describes the net format ( text、image、sound、animation、film) and link information with other pages.HTML is also regard as the text file, it includes html elements and tags.
XHTML
XHTML (extensible hypertext markup language) is also a sort of tag language for making Web pages, but it’s a new edition issued by W3C in 2000 year. XHTML has been used to instead of HTML, and it’s an application based on XML.
XHTML is more terse and compact than HTML. And it must have well-formedness.
XML
XML (extensible markup language) is a sort of data memory language, it uses some simple tags to describe data. This language is easy for user and his format is very clear.
SGML(the Standard Generalized Markup Language)
W3C
W3C (the World Wide Web consortium) is a international non-profit organization. Their aim is to lead the World Wide Web to its full potential by developing protocols and guidelines.
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