The Perfect System

One of the most common questions people ask when learning about cloth diapering is, "What is the "best" system?" Unfortunately, there is no perfect system. Not everyone has the patience for PFs, and not everyone has the money for pockets. So, here's a breakdown:

AIOs, AI2 (All-In-One, All-In-2)
AIO are a complete diaper. Its basically a cloth disposable. It is absorbant and waterproof. AIOs are they easiest way to CD. AI2 consist of a waterproof shell, and snap in or lay in soakers. The shell is not absorbant, but the soakers are not waterproof. AIOs and AI2s are the easiest way to CD, however they are also the most expensive. I also question how clean they can get, since water can't flow all the way through fabric.

Pockets
Pockets have one layer of waterproof material, and one layer of wicking material with a "pocket" you put an insert into. They are not traditionally absorbent on their own, you must stuff with an insert. Pockets are more versatile than AIOs, because you can adjust the absorbency for nights and outings, or other special circumstances. They are usually a bit cheaper than AIOs, but not always. They do require a bit more work though, because you have to "stuff" the insert into teh pocket before wearing.

Fitteds
Fitted diapers are shaped to fit baby and will usually include some form of closure, either snaps or aplix. Fitteds are often bulkier than PFs, but also easier to put on, and sometimes more absorbant. You will need a cover to make fitteds waterproof. Fitteds are perfect for under wool, but any cover works well with them.

Pre-folds, contours, and flats
Flats are simply large squares of cotton or other fabric that you fold many times to fit baby. Pre-folds are less work, they are partially folded and then sewed so you will have many fit options, but not quite so much folding to do. PFs and flats are most likely what you were cloth diapered with, if you were CD as a baby. Contours are many layers of fabric that are sewn together in a shape that fits baby, no folding required. All three will require a cover to be waterproof. You may also choose to close your PFs, contours, and flats with either pins, or snappi.

I think that the perfect system is a mixture between all of these things. In my own "stash". I have 6 PFs, 5 fitteds, 5 contours, 2 AIO, 2 AI2, and a bunch of pockets.