Fitteds and prefolds are absorbent cloth diapers, but require a separate diaper cover to create a waterproof system.
Fitted cloth diapers are very absorbent diapers that are shaped and contoured to fit your baby. They are usually made of wonderfully absorbent materials, such as hemp or bamboo. Being so incredibly absorbent, fitted cloth diapers are especially great for heavy wetters and night-time diapering. They use elastics in the leg casings to achieve a snug fit, and usually employ a snap or velcro closure around the waist. A waterproof diaper cover is required.
Prefold diapers are the most economical choice in cloth diapering. They are basically several layers of cotton (or other absorbent fiber) sewn together in a large rectangle shape. Once you've gotten the hang of folding a prefold around your baby, you'll discover that this style of diaper is truly a wonderfully absorbent, very economical diapering option. A waterproof diaper cover is required.