Use the * (asterisk) to find variant endings to search terms.
drama*
will retrieve: drama, dramas, dramatic, dramatically
Use " " (quotation marks) to keep phrases together.
"crown heights"
Use OR between synonymous or similar terms
theater or theatre
Subject Headings or Descriptors are standardized terms assigned to concepts for the purpose of searching in databases.
They can be more effective and efficient than keywords alone because they are assigned by humans, not randomly occurring.
Selected examples from the OBIS & OhioLINK Catalogs:
American Drama - 21st century
[nationality] Drama
Political plays
Theater - political aspects
Theater and society