Background tables function as repositories of records, primarily hold the static data that is used in process tables, and contain little to no associated business processes or workflows. In short, the data stored in background tables is used to directly support other tables, which are referred to as process tables. Although data in background tables isn't changed by business processes or workflows, it is still created and often updated by power users. A good example of a background table that appears by default in the Standard System Demo is the People table. Records in the People table represent employees or external users, and aren't consistently being updated from the results of a workflow, like Contract and Task records are. Like most background tables, People record data stays relatively static, but can still be updated manually when necessary. Some examples are when an employee receives a promotion and their Role changes, or they get married and choose to change their last name.
The blue text in the diagram below represents the background tables in the default CLM table structure of the Agiloft standard system demo.