In EBSCO databases, some searchable field codes are word indexed, while others are phrase indexed. The database help file located via the Help link in the upper right corner of the database will indicate which searchable field codes are available, as well as which are word or phrase indexed.
A phrase indexed field code will search for your term(s) as an exact match within a record.
For example, in some databases, the field code JN is a phrased indexed field code which searches the source section of citations. In these databases, a search for JN Time can only return records whose source is the journal "Time."
A word indexed field code will search for your term as a keyword within the specified field. For example, the field code SO is a word indexed field code in some databases, which also searches the source section of citations.
A word indexed field code may return results which had either an exact match or a keyword match for the term(s) you entered. The search for SO Time may return results from the journal "Time" or from a journal containing the word “Time” such as the journal "Time & Society."
This also applies to the DE and SU searchable subject fields as well. Both SU and DE search subjects, but DE is indexed and searches for the whole phrase.