Information finding tools:
What are fields?
Each piece of information from a citation, from an index or database, falls within a field. For example, citations are made up of an author field, a title field, a publisher field and a date field.
Most databases allow users to search using fields. These are usually indicated by tags, for example: AU = author, TI = title, SU = subject, SO = source (name of book or journal).
For example: Database - Academic Search Premier (EBSCOhost)