Learn The Lingo

Its like another language.....

I hope this helps.

Now that I've written it out in full, the acronyms are pretty self explanatory, but in general these are nappies that have a method of adjusting the rise length as well as the waist of the nappy so that they can fit right through from NB (3-4kg ish) to toilet training (16kg ish). Most commonly this is achieved with snaps (domes / poppers) but sometimes various methods of adjusting the leg elastic length are used instead.

There is a lot of confusion as to what is the difference between these 2. Ill tell you a secret. There is no difference. They are the same thing. It is more how you use it that determines its name.
Inserts / Boosters are generally pads made up of multiple layers of absorbent fabric (most commonly Microfibre, Bamboo/Nylon Terry, Bamboo/Cotton Fleece, Hemp/Cotton Fleece, Cotton) that are "stuffed" (inserted) into a nappy to provide absorbency.
They are also often added to flat, fitted, preflat or prefold nappies (either inside or outside) to "boost" their absorbency.

Is what you use to add a waterproof (or water resistant) layer over any nappy that doesnt have a built in waterproof layer.
These can be made of PUL, (or other soft flexible waterproof fabrics) wool or fleece.
They can be pull on, or wrap around and secured with velcro or snaps.

Is an extra line of elastic in from the leg elastic of the nappy or nappy cover.

Note - While some people swear by double gussets, I don't put these in Butternutbaby nappies, because personally I find them to be a lot more hassle than they are worth. I found they do very little to improve performance, but DO create a lot more work for cleaning (getting the poo out of all those extra gathers is a pain) I also found that the additional elastic and gathers irritated babies skin.

Is a shaped, fully absorbent nappy, often with separate inserts. They do not have a built in waterproof layer so need to be used with a cover over the top. While these can be used full time, they are most commonly used for night nappies.

A modern version of a flat nappy. These are a rectangle shape, made from stretchy absorbent knit fabric and have "wings" cut into them to make folding and fitting easier than traditional flats. Easy flats can fit any size and can be boosted to suit pretty much any absorbency requirement, so are a great newborn and all ages night nappy.

Think old fashioned nappies - a square of fabric. Traditionally these are either Flannelette or Terry Towelling. Modern versions are often woven bamboo fabric or various stretch fabrics. Flats can be origami folded to use the traditional way or can be pad folded and used just like that with a fitted cover or even stuffed into a pocket nappy as an intsert (Bonus of using them like this is that they are really absorbent but still dry a lot faster than most inserts)

These are without a doubt the most popular type of modern cloth nappy. The outside layer is breathable, water resistant PUL. They are lined inside with a soft fabric that goes against the skin. The space between these layers, creates a pocket where absorbent fabric is stuffed. (Generally inserts, but pad folded flat nappies or prefolds are also popular due to being faster drying than inserts)
While some brands do still offer bamboo (viscose) or cotton lined pocket nappies, these are loosing popularity to more modern hydrophobic fabrics that create a stay dry layer against babies skin. (AWJ - Athletic Wicking Jersey, Polyester Suede, Charcoal Polyester Fleece, Polyester Fleece)

Liners are an optional layer of material that is placed between the babies skin and the surface of the nappy. There are many kinds and people use them for 2 different purposes

To make cleanup of poop easier. (again, it is a matter of opinion and personal preference as to whether they actually make it any easier or not) - In most cases, when used for this reason, liners are of the disposable variety. The idea being that you simply pluck out the poo, all nicely contained in the liner and dispose of. This SOUNDs like a great idea I know, but there are a couple of things to to keep in mind.

Disposable liners are NOT flushable (even if they say on the pack that they are - by necessity, wetness does not break them down and they will block your plumbing). So that means putting them in your rubbish bin. POOOHEY!(Did you know by the way that you are not supposed to put human waste in your household rubbish? I know people do, but you are actually supposed to remove any solid waste from even disposable nappies, before putting in the bin)
Disposable liners are hydrophilic - they will sit wet against your babies skin and so can make them more susceptible to rashes
You CAN get washable liners (and some of them are hydrophobic, so stay dry.........and again, it is all personal preference, but I cant see how it is any easier to wash a liner than to wash the inside of the nappy.
The 2nd reason people choose to use liners (reusable, stay dry ones) is to provide a stay dry lining in nappies that otherwise do not have one (most fitted, flat, prefold, preflats etc)
Dry Pailing

Is the modern method of storing cloth nappies ready for washing. Dry pailing is the opposite of soaking nappies, and involves putting the dirty nappies inside an airy basket. If your home does not allow for an open airy basket (Your laundry is in your kitchen for example or outside the house and not suitable for poping nappies into one at a time) then you can still use a lidded bucket or a wet bag, but it is still recommended to store them dry. You can store dirty nappies, this way for 2 days.
Rise adjusters

Are the snaps / studs / poppers on the lower front of the nappy and are used to adjust the height of the rise (and the leg opening) making one nappy able to fit a wide size range - ideally from NB (or close to it) till toilet training.
All In 1 Nappy (AIO / AI1)

An all in 1 nappy is when you have waterproof outer & absorbency all sewn together into one article. These are convenient in as much as there is no folding or stuffing required, but a less popular now due to being a little more difficult to wash and slow drying.
All In 2 (or more) Nappy (AIT / AI2)

This is a relatively broad term that captures any nappy set up that requires putting multiple pieces together, where the waterproof / water resistant shell and the absorbency are separate. eg...
Prefold Nappy

Is a rectangle woven fabric, similar to a flat nappy, but is divided into 3 portions, with a thicker "pad" section in the middle. These can be use in much the same way as flat nappies, but do take longer to dry.
Tri Fold Insert

Is a rectangle shape, usually 2 layers, that when folded in 3 makes a 6 layer insert - but easier to dry than if you sewed 6 layers together