Target audiences can be used for various purposes:
Counting:
With a selection, you can quickly and easily determine how many contacts meet certain criteria. With just a few clicks, you can get an overview of how many contacts, for example, have performed a specific action or how many contacts have a known postal code.
Exporting:
The result of a selection can be exported, such as exporting it as a CSV file or directly into a connected database. In such cases, it is referred to as a manual export.
Organizing:
A selection can be saved as a group. It can be found under Database > Target audiences and can be used as a criterion for other selections, for monitoring the size of the group, or for automatic export to a connected system.
Automating:
The rules you build here are the same rules a workflow uses in its conditions, so anything you can select as a target audience you can also branch on inside an automation.
Deleting a target audience:
A target audience is a saved selection, not a container. Deleting it removes only the selection; every person stays in your database and keeps counting toward your contact limit. An audience that is still used by a planned email or as a rule in another audience cannot be deleted until that use is removed. To delete or unsubscribe the members of an audience, see Deleting people and cleaning up your database.