Document Metadata Metadata is information about information, so document metadata tells about the file or page, for example, the author, date, and topic. Adding metadata to documents and indexing the fields provides substantial benefits, allowing searchers to limit their results in useful ways. For example, searching for word processor reviews on an information site, you want just recent reviews rather than news. Search tools that store these metadata values allow searchers to improve the precision of the search and get fewer, more relevant, results. For more information, see the Metadata page .
Structural metadata refers to the tags within the document.
However, this might be the author of a book described in the document, the author of a movie review, and so on. This metadata can also be searched, if the indexing application can recognize and store it correctly. Web search engines should support the format, in an appropriately limited way, to provide free-text access to the indexed documents without requiring external engines to learn their syntax. On the Web, there are several conventions that page creators and search engines already use for indexer control, and it's unclear how well XML fits in with these. XML documents may want to use these as well.