Most household security systems focus on the house. They have motion detectors inside the house, glass break alarms etc. They show a part of the driveway and the front/back porches in some cases (outdoor cameras are usually more expensive). We have several trail cams in addition (to capture the area past our fence where people keep dumping trash, to capture the area near our mail box, etc). It just wasn't cost effective to buy the wireless cameras that go with our security system for outdoors, and the trail cams can be moved (there's a cat getting into our backyard and we'd like to know which one it is - so we moved a trail cam). They are very handy. Trail cams are motion activated. We have both visible and well hidden ones. They have pretty sharp views of night time scenes, as well. It's kind of a pain having to go retrieve the card inside to see what's going on - but the huge amount of data stored from our house cameras (we have three) is daunting as well. For my DH, it's just way easier to go and retrieve the card when he sees the trash or evidence of the cat.