Trail downhill enduro fat plus normal. Is there a normal?

What’s the difference between all the mountain bikes? There’s different wheel sizes, different size tires, different kinds and amounts of suspension, different materials, different geometries, different… what happened? We moved, there’s a big forest preserve nearby, I want to go bombing around in there. There are trails and some hills and a little river and sometimes it’s muddy or snowy or whatever. Is there a, what, a usual kind?