Budget is a key factor in this. For the most part you can store days on a modest computer with proper set up. Live video and high bit rate becomes more challenging.
cctvcamerapros.com has some items that show how much storage you get out of what bit rate and FPS.
They are also very helpful, I went to a free seminar they did.
Outdoors adds a harder mix to the formula. Condensation, temperatures (most cameras will not record around freezing), and IR attracting nests blocking the lens/changing the focus. Level of optics is also a big gap. Getting face/license plate reproduction is a lot more pricey than typical cameras which will not let you read a license plate usually and don't offer enough resolution to properly identify anyone unless they get caught and a comparison is made. Better cameras can go to print with a nice 'wanted' flyer.
