Two part diaper systems have a waterproof cover that is used with an absorbent layer of some kind. Some systems have snap in inserts that attach to the waterproof diaper cover. Other two part systems include prefold cloth diapers and cloth diaper covers, fitted diapers and covers, and systems such as the Flip system that have a variety of inserts that are simply tucked inside the cover for each use.

Two part systems are typically cheaper than all in one cloth diapers or pocket diapers - although luxury fitted diapers and wool diaper covers are not an economy system! They will cost you a bit more, but will still save you money over throwaway diapers.