1. An information processing apparatus for processing document data described in a structured language, the information processing apparatus comprising: a storage unit configured to store at least a part of the document data; a parsing unit configured to parse the at least a part of the document data in order to extract information contained in the document data, wherein the parsing unit parses the document data from a group of one or more nodes having a high importance to another group of one or more nodes having a low importance in a network structure represented by the document data.