WeaponZero’s got it covered 10 ways from Sunday (maybe Ben will post your paper in the “recommended reading” area??) , but some basics:
Leather provides the best possible protection short of not actually riding a bike. And it can usually survive a moderate fall without having to replace it. It also looks damn cool…from a basic jacket to a full suit, nothing screams “motorcyclist” more. It is however expensive for the good stuff, and can be hot (even the perforated models) in the summer.
Textile provides less protection, but is less expensive. It’s designed to sacrifice itself in a crash, so you’ll (hopefully) come out unscathed, but your gear will be shredded. Can be hot in the summer too, but there is also mesh textile, which provides less protection, but is very cooling. Textile is often more bulky than leather, and you’ll make less-cool swooshing noises when you walk around.
I usually wear textile, but I do have a leather jacket for the fall/winter.