what is xml schema
An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself.he primary purpose of a schema language is to specify what the structure of an XML document can be. This means which elements can reside in which other elements, which attributes are and are not legal to have on a particular element, and so forth.