An application or object that uses an MTS object is referred to as a client of the object. It is important to understand that this is a relative term, and describes a relationship with a specific object. For example, when MTS object A uses MTS object B, the object A, while still an object, is also a client.
Clients that run outside the direct control of the MTS run-time environment are referred to as base clients.
Clients and base clients: The Order object is a client of the Payment object
Base Clients, Base Clients vs. MTS Components