One of the most confusing aspects of doing online research on cloth diapers is that the language used is often not consistent between websites. If you are feeling confused about some of the cloth diaper terminology that you've come across, take a read through this glossary of common cloth diaper terms.


This stands for all-in-one. In the cloth diapering world, this refers to an all-in-one diaper. This is an inclusive cloth diaper that functions entirely on its own. The absorbent component and waterproof component are attached, making it as easy to use as a disposable diaper. It requires no extra liners and fastens with either hook and loop or snap closures. An AIO could be a sized diaper or a one size diaper.


This stands for all-in-two. Sometimes called hybrid diapers, an all-in-two is a diaper that has a detachable insert. When the insert and cover are put together (usually they snap into place), they create a complete cloth diaper. Inserts and covers can be attached ahead of time, making diaper changes as easy to use as a disposable or all-in-one diaper.


This stands for polyurethane laminate. Polyurethane laminate is a compound fabric that is made by laminating a cloth fabric to a thin film of polyurethane. This creates a waterproof fabric that is ideal for diaper covers. Most diapers that we carry feature a PUL cover that when paired with an absorbent component make a durable and leak-free diaper. PUL is also used for a range of other products that need to be waterproof, such as outerwear clothing and shower curtains.

Fitted Diapers

Fitted diapers are the absorbent component of a 2-piece cloth diaper. These contoured absorbent cloth diapers that either snap closed or uses hook & loop, Aplix or Velcro and will sit directly against your baby’s skin. . When paired with a waterproof cover, you have a complete cloth diaper – one part absorbent and one part waterproof.

Diaper Covers

Diaper covers are the waterproof components of cloth diapers. Sometimes part of an attached to a diapers as in an AIO or sometimes separate,as in an AI2 or as a separate unit to go with a fitted or sized diaper or with a flat or pre fold diapers. Diaper covers are an essential part of cloth diapers; they keep messes contained and prevent leaking.

Flat Diapers

Flat diapers are the most traditional and basic type of diaper. These are diapers that lie flat regularly and can be folded to fit. Flat Diapers can come in the form of cotton flannel squares or cotton prefolds. When combined with a waterproof cover, a flat diaper makes a complete absorbent and waterproof diaper.

Hook and Loop

Hook and Loop is an alternative term for a fastener that most people more commonly know as Velcro. Velcro, however, is a brand name rather than a product (like Kleenex). Hook and Loop is a commonly used fastener for cloth diapers.


Aplix is an alternative term for a fastener that most people more commonly know as Velcro. Velcro, however, is a brand name rather than a product (like Kleenex). Aplix (also a brand name) is a commonly used fastener for cloth diapers.


Prefolds are a type of flat diaper. Similar to a flannel square, pre-folds lie flat when not in use and can be folded onto your baby and the diaper is held together with a Snappy and a diaper cover. Prefolds have multiple layers of fabric to increase absorbency. They are simple cotton diapers that are durable and functional and are available in three sizes. Flannel Squares are one size and can be folded many ways to fit onto any size baby.

Pocket Diapers

Pocket diapers are cloth diapers that have a pocket opening between the outer and inner layer of the waterproof cover. When a cloth insert is put inside of the pocket, it creates a complete absorbent and waterproof diaper. Pocket diapers are great for customizing absorbency, as you can add extra absorbent components if needed. The pocket is traditionally made of polyester.


A wrap is another term for a diaper cover that closes with Aplix, Velcro or Hook & Loop. Sometimes attached to the absorbent component and sometimes a separate piece, wraps are the very necessary waterproof component of cloth diapers.


This stands for one-size. It is pretty common for cloth diapers to be one-size that is adjustable to fit babies between approximately 7 – 35 lbs. This means that the same diapers could fit your baby from birth right through to potty training.