Subsystem

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A subsystem is a system within a system; oftentimes, when an individual member has a system of their own, such as a nested system.

This can also refer to independent groups within a larger collective (although this is more commonly described as a layer, subsplit, or sidesystem).

Subsystems can experience any form of plurality as well.

History
The term has been used as early as 2004.

Related Terms
Subsystem can function as an umbrella of sorts for subgroups within a system, including the terms listed above. Quite a few subsystems are median in nature, creating terms like ringed subsystem.

Members of a subsystem are sometimes known as subalters.