XML Structures:

• XML includes a mechanism for defining rules that control how documents are structured

• In jargon, these are called Document Type Definitions(DTDs).

• DTD has the list of the element types thatare to be used in the document such as tags, root elements (more on this later)

• XML has to have well defined structure

How do we check if we have well defined structure?

• A utility program called an XML parser tests whether or not the document meets the prescribed rules