Keywords also describe a subject. However, they are not standardized by anyone. Keywords are generally those words that someone looking for information, such as yourself, selects as a good description of the information s/he wants to find. They can also be the terms that a researcher has listed as important descriptors for the information s/he has produced.

In online catalogs and electronic indexes, keywords are found anywhere in the bibliographic record. In print indexes, except for the Keyword In Context (KWIC) and Keyword Out of Context (KWOC) indexes produced in the 1960s and 70s, keywords will only appear if they are the same terms as the subject headings.

Keyword searching is a product of the computer age. In online catalogs and electronic indexes, a keyword search scans the entire bibliographic record. No matter where the keyword you have selected appears, that record will be retrieved. As a result, a keyword search retrieves a large number of results. If the term you chose as a keyword is one which can be used in multiple contexts, many of the results you retrieve will be irrelevant to your project.