So, as the title says... I'm confused about cloth diaper options.

All in ones I think I mostly understand. It's one piece that goes on exactly like a disposable, but can all be thrown in the wash when it's dirty, correct?

But, how do the pocket ones work? Are you supposed to be able to change out the insert part without changing the outer part? Or does the outer part get dirty just like an all in one, so it gets thrown in the washing after one nappy change too?

The brand I'm mostly looking at is bum genius, and I want to make sure I understand it all completely before ordering, because I'm going to have to get my in-laws to ship them all the way out here for me, which makes any returns impossible.

Sorry if there's already a thread on this, I searched and couldn't find anything, I promise!