DOM
sAx
SAX : it is designed only for reading XML documents and is not supported by any parser built into a maintstream web browser. therefore you may need to write a lot of code for complex queries. downloading a sax parser is also an additional overhead. sax parser is designed to prevent certain lexical information from reaching readers. this includes the original order of characters and attributes and comments in XML documents. therefore, such information needs to be handmade SAX parser also hides the contents of the DTD in the docs no memory support no query features hence difficult to deal with ID and IDREFS
startDocument startElement characters endElement comment endDocument