A database is made up of records. A record is a description of an item.

In TOPCAT, each record describes an item in the library - a book or a map, for instance. In an index, each record describes an article or perhaps a book chapter.

Each record is made up of fields. Fields identify a particular part of the record. In TOPCAT there is a field for the title, a field for the author, a field for the call number, etc. These fields are searchable, so that we can specify where in the record we want to look for the piece of information we're seeking. This helps to make our search more specific.