What is the difference between DOM (Document Object Model) and SAX (The Simple API for XML)?

The DOM (Document Object Model) and SAX (The Simple API for XML) are the most common APIs used to work with XML documents. The DOM defines a set of interfaces and methods used to view an XML document as a tree structure. The SAX API defines the events and interfaces used to interact with a SAX parser.

XSLT and XPath use a similar tree view of XML documents. Currently, most XSLT processors are based on DOM parsers. In the near future, however, we’ll see XSLT processors based on SAX parsers. This means that the processor can start generating results almost as soon as the parse of the source document begins, resulting in better throughput and creating the perception of faster service.