(AIO)-
All in One - it's all in one piece and similar to disposable diaper. AIO known as user friendly and mostly they are use in daycare center. It's made up of an outer waterproof layer and an inner absorbent layer. Mostly it's thick because of the many layers sewn and it takes long time to dry. No pin and cover needed for AIO diaper.
Pocket Diaper~ has 2 layers and outer layer and inner layer. Mostly in outer is waterproof but some hide the waterproof fabric and use the printed fabric for outside layer. The pocket diaper has opening so the insert is stuffed into the pocket. You can use terry cloth, fleece, hemp and many more for the soaker. I like pocket diaper because you can control the absorbency by adding more doubler/ insert when needed.
Pre-Folds~ are rectangles shaped and flat. It requires waterproof cover and folding, you can use snappy and pins in pre-fold. It is all purpose and you can use pre-fold as burp cloths, inserts for pocket cloth diapers and you can use as dush rags.
Fitted Diapers ~ Have elastic around the thighs and at the waist. Easy to use due to snap and velcro closures. It requires waterproof cover and it's little expensive compared to pre-fold. Fiited diapers is made up of several layers of cloth.
Diaper Covers~
Use to pre-fold and fitted diapers to prevent wetness getting on to your child's clothing. They come in many forms such as polyester. vinyl, wool or fleece. Mostly they're in velcro and snap closures. You can use it several times after air dry in several uses.