Web Search returns descriptions of each hit that is listed on the search results page. By default, the following information is returned for each result:
The first three fields are taken from the content of META tags in HTML documents or from document summary fields in other document types such as Word* or PDF files. If these tags or fields are not defined, Web Search will try to find the first heading and begin selecting words. If it can't find a heading, then it begins at the top of the document and selects the first 255 relevant display bytes as the description.