From Psychology Today: (for the whole article, click here)

Internal Family Systems was developed in the 1990s by family therapist Richard Schwartz, Ph.D., who developed the concept of an undamaged core Self that is the essence of who you are, and identified three different types of sub-personalities or families that reside within each person, in addition to the Self. These include wounded and suppressed parts called exiles, protective parts called managers, that keep the exiled parts suppressed, and other protective parts called firefighters, that distract the Self from the pain of exiled parts when they are released. For example, an exiled part may be the trauma and anger of earlier abuse, emotions that are suppressed by the manager, while the firefighter may be an alcohol addiction or behavior such as overeating that distracts the client from facing and re-experiencing those uncomfortable emotions. These parts can be healed, transformed, and better managed by the Self by achieving the three goals of IFS:

1) Free the parts from their extreme roles

2) Restore trust in the Self

3) Coordinate and harmonize the Self and the parts, so they can work together as a team with the Self in charge.