The flip system has snap in absorbent liners. So you can possibly reuse the cover a few times before washing by just changing the liner. With a pocket diaper, you have to change the whole diaper every time. Basically a pocket diaper is a waterproof cover with a thin non-absorbent liner sewn in that you stuff something into - either a special insert (typically microfiber) or a cotton prefold. Pocket diapers are nice because they are really easy to put on and change and they wash very well because the absorbent insert is washed outside of the diaper. I’ve not tried the flips but they are very similar in concept to a folded prefold or flat diaper in a waterproof cover.
