Terminals are used to define characteristics of a single terminal:
Each terminal must be assigned a Settings record; the Settings record determines the options and configurations of a group of Terminals.
Terminals can also roll up to a Master Terminal. This is useful when you want to pool cash drawers or printers.
The Device Id on the Terminal record represents the Device Id of the iOS device (from the Registration Screen). This is used for authentication and licensing purposes.
Terminal records that are inactive or blank are not counted towards licensing.