Stacy, it's mega confusing at first cause there's so much out there and so many brands. You can get all in ones where everything is built in but you can add booster liners if they wet a lot, and disposable liners for easy clean up of poo. Then you can get these in sizes or you can get them birth to potty and there are poppers to adjust the length and width of the nappies.
Then you can get separate nappies with a wrap (you put on over nappy) to make it water proof. Again you get liners with these generally but you can get boosters to add in. Then there's different materials also! It's all so confusing lol. I bought yesterday a set of 8 birth to potty all in ones as I will test them out on my toddler then can always use on baby too, and I got 5 bamboo nappies and pack disposable liners. I just need a couple of wraps. Girl I spoke to said she used a wrap upto 5 changes so not too bad (unless they explode lol). Bamboo is supposed to be best absorbing, you can get microfibre which dries really quick, and cotton. Mine I got were little lamb, but I want some called pop ins too which I like the look of. Sorry I've probably confused you even more ha ha. X
Just to add apparently bf poo is a lot easier to clean off nappies too due to its water content or something like that. X