What is XML?

XML is the Extensible Markup Language. It improves the functionality of the Web by letting you identify your information in a more accurate, flexible, and adaptable way.

It is extensible because it is not a fixed format like HTML (which is a single, predefined markup language). Instead, XML is a metalanguage—a language for describing other languages—which lets you design your own markup languages for limitless different types of documents. XML can do this because it's written in SGML, the international standard metalanguage for text document markup


Keywords: XML ,HTML,accurate, flexible, XML is a metalanguage,SGML,text document , adaptable way

Thanks.........

Hello,
What is the easiest/best php function to validate the xml? I've been searching the internet but haven't had much luck finding a good example.