Therapy?

Does anyone here know anything about Internal Family Systems therapy? The thumbnail description I was given makes it sound like it has some things in common with the way DID was viewed back when it was still called Multiple Personality Disorder where all the personalities conform to a standard set of Purposes, so you have The Innocent One and The Organized One and The Aggressive One, except that instead of full-on headmates you have the internal parts of your personality and I have... issues... with that framing.

On the other hand, it was a fairly quick thumbnail description, so it's entirely possible there were some words crossed here.

Anyone know enough about it to explain what I'm seeing?