XML (Extensible Markup Language) is a general-purpose specification for creating custom markup languages. The term extensible is used to indicate that a markup-language designer has significant freedom in the choice of markup elements. XML’s goals emphasize representing documents with simplicity, generality, and usability over the Internet. XML has been used as the basis for a large number (at least hundreds) of custom-designed languages. Some of these, for example RSS, Atom, and XHTML, have become widely used on the Internet. XML dialects (often packaged in archive files) are becoming the default file format for office-productivity software packages, including Microsoft Office, OpenOffice.org, AbiWord, and Apple’s iWork. Lets discuss advantages and disadvantages of XML.