Uses of xml?

[sc_king]

Can anybody explain the uses of xml?
When should we use it?
How does it differ from a database?

[Kor]

XML was designed as a transfer language medium from a data base to another. You may build a data base written in XML, but, on the one hand, it is not a secure base (if used alone), on the other hand some say that XML is not quite practical when you want to store a huge amount of data.

[NogDog]

I would go as far as to say that it's totally impractical for storing, searching, and otherwise processing large amounts of data, when compared to any modern RDBMS. It's main use is as a standard way to transfer data between disparate applications that might not use the same data storage/representation mechanisms, internally.