Internal Family Systems, or IFS, is a Freudian-descended model of the psyche and psychotherapy method based on the idea that the mind is split between parts called exiles, managers, and firefighters. Therapy consists of methods for allowing these parts to “talk” to each other so, for example, exiles can be reintegrated.
Wikipedia as a more thorough introduction to the IFS model.
For a related technique developed by CFAR, see Internal Double Crux. Rather than thinking of the mind as an entity with one set of goals and beliefs, IFS includes many independently acting components, each of which might have varying goals and beliefs; see subagents for the more general form of this idea.