Records are composed of fields . Every database covers particular topics . Take the time to find out which topics a particular database covers. Choose a database that is appropriate for the research you are doing. Searching a database which does not cover the topic you are interested in is a waste of your time.
Every database covers a particular time period .
Each database covers material from a particular period of time. This period of time is sometimes referred to as a database's coverage . Be aware of when each database's coverage starts. You may need to consult print resources to locate your materials. However, you need to know how frequently each database is updated.