I finally realized today why it can be tricky for some folks to remember the difference between "All in One" cloth diapers and "One Size" cloth diapers.
All In One (or, AIO) to some people means the diaper is all sizes in one diaper. However, when speaking about cloth diapers, All In One implies that the absorbent layer(s) and the waterproof layer are somehow permanently attached.
For example, our bestselling All In One diaper is the OsoCozy AIO. Here's a picture:
Some other brands use a flap-style construction, like the Bottombumpers All In One, like this:
Flaps help reduce drying time, the #1 downside of All In One diapers.
One Size Diapers combine multiple sizes into one diaper, and come in all styles: prefold, contour, fitted, pocket and all in one.