Stronger tool for XML data model specification than DTD; Offers the opportunity to:
Separate type concept (element type for example) from its occurrence (element with particular name) - not possible in DTD
Offers more primitive data types.
Allows to use namespaces.
Allows to specify content model (elements) a more accurate way.
Allows derivation (inheritance) of new types.
Allows modular schema design and schema reuse.
It has an XML syntax.
