Cover = a ballistic shield. Concealment = the bad guy can’t see you. Cover can be concealment but concealment is not necessarily cover. For example, a car door. It’s not cover: most rounds will go through the thin metal like a hot knife through butter. Also, it’s not concealment: the bad guy can see (and shoot at) your legs and feet. If you’re using a car for cover, the engine block is just about the only thing capable of stopping rounds. Sometimes. Oh, and resist the urge to shoot in the general direction of something just because other people are doing it. Especially if you’re a cop.