Brushing is bar none the most important part of waving, without brushing it is impossible to get waves, even if you get a kit. Brushes pull at your hair and stretch out the curls and since the curls will not stay straight, they go in a in between state called the "wave".
Soft Brushes: Primarily used when your hair is low (week or two after a fresh cut), or for ppl with softer/straighter texts. Im going to put an end to this myth, soft brushes do not give you connections, Starting from a lower (.5 guard lower) cut and wolfing and repeating over and over gives you connections. But i will say this, soft brushes do lay down your hair since it isnt brushing your hairs that are close to your scalp, it only gets that top layer.
Medium Brushes: Great for the in between stages of a fresh cut and heavy wolfing, it feels 50% like a soft brush (or better depending on the brush, bristle, etc.) and 50% like a hard brush (or better depending on the brush, bristle, etc.). Really the medium brush is the best of both worlds, soft, but it actually brushes your hair during the middle to latter stages of a wolfing session. Meds can be used for ppl with softer/ straighter texts that are heavy into wolfing.
Softened-Hard Brushes: These are sort of a hybrid brush, they are in between medium and hard. Primarily used at lower cuts to straighten crooked waves or fix disconnections (you have to soften this brush yourself, all i do is soak it in soapy water over night). Its a great brush to use and i believe its best to have an extra for use in the shower when shower brushing at low hair lengths, it does more work than a medium brush and it isnt as hard as a true hard brush.
Hard Brushes: These are the big time mob bosses of brushes, they do the most work and they last the longest. Hard brushes yank your hair pretty much so make sure your hair is moisturized (water will do) before you go into a prolonged brushing session because breakage may occur. Primarily used when wolfing to deepen waves, it can be used at lower lengths to fix disconnections and straighten out crooked waves. It works wonders when you are showerbrushing, it lays hair down exceptionally well when heavy wolfing.
Shower Brushes: These consist of hard, softened-hard, and medium brushes. Their use is to lay down hair while wolfing while brushing in the shower, it can be any brush, they is no such thing as a brush made for "showerbrushing".
Mini Brushes: These are the little brushes that could easily fit in your pocket. Their main purpose is to brush hard to reach areas such as the crown, back of the neck and side burns/temples. My suggestions is to get one of these brushes if you want a perfect crown, and it would be best to get a double-sided one also
Club, Palm, and Long Handle Brushes: Club and Palm brushes are pretty much the same thing, they do they same thing, have the same britsles. The only difference is the handle on the club brush. Long handle brushes cover more area than the club and palm, but they may mess up connection because they are so long, so if you have a small head then i advise you to not get a long handle. On a good note, long handle brushes work best on the top of the head since it covers the whole top, not just the left or right or middle.