From what I see (and eat) here, there are two main textures of tofu at my grocery store. Silken and Cotton. Silken is very smooth and kind of like custard or jello. Cotton is lumpy (?) like pressed cheese curd that has some little airpockets in it. Or like polenta. (I know my descriptions aren't that good, but that's what the tofus make me think of)

Each comes in various firmnesses (related to how much water is in it) like soft, firm, extrafirm.

I like the silken for desserts or mixing into batters, the cotton for marinating and using like meat. Generally I choose firm or extrafirm, just cuz soft falls apart easily. Sometimes I drain/press the water out of some extrafirm cotton and then marinate it if I want to fry it like a burger.

I also really like tempeh, but that's another story...