Difference Between XML and HTML

There are the following differences between XML and HTML:

XML	HTML
XML is case-sensitive markup language	HTML is not case-sensitive markup language
XML is used to describe the data	HTML is used to define the data
In XML, ending tag can never be omitted	In HTML, ending tag can be omitted
In XML, user defined tags are possible	In HTML, only predefined tags exists
In XML, attributes values must be enclosed within quotation marks	In HTML, quotation marks for attribute values are optional
In XML, if attribute is defined then it should have values	In HTML, attribute can be present without values
In XML, data interchange is possible	In HTML, data interchange is not possible
XML documents are Hierarchically structure	HTML document should have <html>, <head> and <body> tags
XML document are reusable and extensible	HTML document does not supports reusability and extensibility
Modularity can be provided by DTDs	HTML has no DTDs

Advantages of XML over SGML & HTML

XML can be used with exiting web protocols such as HTTP and MIME and mechanism such as URL and it does not improve any additional requirements.
XML is compatible with SGML. Most SGML application can be converted into XML.
Design of XML is formal and concise.
XML is structured, platform independent and support user-defined tags.
XML is reusable and extensible i.e. future enhancement are possible.
XML support data interchange and also has temporary database.
XML is supported by IE 5.0 and above, Netscape 2.0 and above.