What causes for critically successful hacks and critically failed hacks, along with critically failed/successful raids?

I've had quite a lot of critically successful raids, but two critically failed hacks.

What are the elements which cause each of these?

Edit: I understand what each gives and I know for raids its mostly a crew deal but are their any ratios of cloak/scan and crew size that lead to it? (i.e. formulas)

nope no real formulas to it, its just random, much like planet invasions, you always have a % chance to succeed no matter what, so if someone alerts a very nice planet as free for all, might as well try, flip side to that, max % you have to invade a planet is 90% so you always have a chance to fail. same things with raids and hacks, just random.

thank you