Inside an XML Parser

As noted previously, XML parsers come in two flavors: standard, which merely checks that a document is well-formed, and validating, which matches the document to its DTD.

Parsers also come in two basic types: those that form a parse tree and those that merely parse a document as a flat structure. The first type is by far the most common. Although it is not quite as fast as the second type, it is far more versatile. More importantly, it is extensible.