The dominant word is language . The tagging allows the information to be re-created in its formatted structure even if the software that created it is unavailable.
Tags can also point to external entities, such as graphics, image files, or sound clips.
The tagged file is accompanied by a document type definition that describes the tags-the document's architecture. Given a document definition that explicitly declares how each of these tags is to be treated, a parser can be written to translate the tagged structures shown in figure 1 into another form, independent of any software or hardware considerations. Another extremely important ramification of this type of markup is that it captures structural components that influence relevancy ranking in document-retrieval operations. For example, a query term that appears in a title or major section heading is likely to indicate a higher degree of relevance for that document over a document in which the same term appears in a parenthetic aside. 1 illustrates a marked-up sample document and Fig. 2 its output.