I would imagine that there are as many ways these work as there are manufacturers. These are questions to ask of someone who sells them and installs them.

Are you talking business or residential.

I sold the security systems at Time Warner Cable & there are many options. All for a price. You can record constantly & save to the cloud. The space you purchase to use on the cloud will depend on how many days you wish to keep. Most people do 5 or 7 & just start recording over. You should know by then if something happened you need to view.

You can also watch the cameras live on your smartphone. Some cameras can be motion activated, some record all the time & some can swivel & record. Depends how much you want to spend for the system, cameras, monitoring & cloud storage.

The technology is constantly evolving. I have an older system and my 4 cameras record to a recorder - I imagine it is a hard drive - in my house. Mine are motion activated and get erased or copied over after a set amount of days or weeks depending on how I set the software. I think some of my cameras also have an internal recorder.

If you are looking to install a system, rather than trying to understand everything that is possible, figure out what you want to accomplish in terms of recording, and then you can look for a system that does that.

Also, wanted to add: while the cameras are motion activated, you set how long in advance of the motion you want to camera to record - 15 seconds, for example.

this is residential and if the camera is pointed at the door will it record other things in the room or just who would be coming in the door. I am just wondering because this is the first time I have ever been in a house with a camera. I think it made me self conscious or a little bit nervous

I think it made me self conscious or a little bit nervous

I think you are on camera a lot more than you are aware of.

Watched

Also, wanted to add: while the cameras are motion activated, you set how long in advance of the motion you want to camera to record - 15 seconds, for example.

graywings123: Your post confuses me. How can a motion activated camera know when it is 15 seconds prior to the motion that activates it? I get setting a time for it to run after the motion starts the recording. Or did you just intend it to mean that you make those settings during the system set-up phase?

I would imagine that the camera is recording to memory constantly, but then erasing it 15 seconds later. So when it detects motion it isn't starting the recording, it instead is stopping the erasing.

Ah. That make sense. Thanks, bob.

Ben, depending on the camera & lens it might capture a small image or a large image with wide angle.

Storing the recordings take up space, but it's preferred to record in HD. High definition. Some recordings are so grainy you can barely make anything out. HD recordings & HD cameras make it clear as a bell.

Lucille, I know we're on camera most of our life. On the roads, shopping, banking, restaurants & such. But it's weird to have cameras in the house. Makes you think should I wear underwear & a robe just walking to the kitchen?

I had a friend who tracked her husband with their security system. She would watch the cameras and see when his truck left. And she would monitor the door sensors to see what time he let the dog out.

Speaking of remote dog monitoring, I recall reading a story about scammer dog walkers, who would sign that they had walked a dog but not actually do so. One owner caught that by monitoring the dog's location after it started having uncharacteristic bathroom accidents in its crate.

This is very timely as there was an incident yesterday on the news where a woman's home was broken in to not once but twice in two days by the same person! He unknowingly looked right into the camera and now authorities have a perfectly clear image of who it is. It even recorded voices so they also have him talking on the phone to someone outside who was watching for police and now know they need to look for 2 people. The video has been played on the news stations so it's just a matter of time before they're caught.

I used to think having camera's in one's home was weird, but after seeing several incidents on tv, I can see why they are getting so popular!