Closed Circuit Television (CCTV) cameras are nearly present everywhere today, even most spaces in cities in Pakistan. Being the most simple way to monitor businesses, homes, schools, prisons and the streets. Strategic placement is important for maximum visibility of a space. With newer technology, the CCTV cameras have also become compact and full of all kinds of upgrades.
Some CCTV systems are based on a wired setup and the cameras require power and a Digital Video Recorder (DVR) in place to store the audio/visual information. Others are standalone cameras that have the ability to record onto an SD card that fits into it. Most current systems have Wifi, meaning you can watch the space under surveillance from anywhere as long as you have internet access and some even come with apps on your smartphone so you can surveil on the go. Most cameras now are HD, with good resolution and higher frame rates making for more smooth video. A lot also have weather protection and night vision, so the outside areas can also have cameras despite any harsh weather they might need to endure around the year. Motion detection has become common as well, so some can be on standby until they sense movement and start recording from that point on. This works for places that generally do not have footfall but in specific cases might need to be kept secure like a storage warehouse. There are also standalone devices that have 2-way audio, meaning you can also talk to the person/s in the space being monitored.
The important bit is to figure out what system works better for your personal requirements or what the requirements of the space are. The larger CCTV camera systems can be complex to install with wiring and all, which makes more sense for the outdoors or banks and such. Homes could easily be secured with simpler standalone cameras. There are also differences in price with these 2 systems since the standalone's have more functions built into one unit the per camera price can be higher.