LibAnswers

Subject searching allows you to search a database or catalogue using pre-defined categories, also known as subject headings or controlled vocabulary. Using a database's subject headings allow you to search more precisely, to retrieve more targeted results.

The list of subject terms used by a database, also known as the thesaurus, which will vary according to the database and can include thousands of terms.  For example, Medline (a medical database) uses a thesaurus called Medical Subject Headings (MeSH), which only includes subjects related to medicine. Business Source Premier (a business database) uses a thesaurus called Business Thesaurus, which only includes subjects related to business. The thesaurus is regularly updated, to reflect new trends or new research in a subject.

Each article in a database may be assigned multiple subject terms.  To narrow your search, consider combining multiple subject terms, or combine subject terms with keywords, using Boolean operators.