Pocket diapers are the most common style of diaper used today. Pocket diapers are much like AIO's, except you are able to remove the absorbency in order to make laundering easier and to cut down on drying time. They have an outer waterproof layer as well as an inner stay-dry layer such as microfleece. There is a pocket opening which allows you to add as much or as little absorbency as you need.
