1- The number of Frames Per second your DVR (Digital Video Recorder) is capable of handling. First understanding what that means, A real time second of video is 30 Frames. so a recorded second or video motion that doesn't skip is 30 Frames. So if your CCTV camera system is capable of handling 30fps that means you can record only one camera real time otherwise the 30fps will be divided into how many cameras they system might support. So when looking for a good CCTV Surveillance system make sure you get a system that does 30fps for each camera. so if you are looking for a 4 a good CCTV security camera system look for a 120fps DVR capable.

2- TV Lines supported by the CCTV cameras. A CCTV camera's quality is measured by TV Lines, which is the number of horizontal TV lines the camera produces, and of course the higher the clearer and better picture. the average quality is 400TVL, 420TVL is good picture quality, 480TVL is higher quality and more is even Better. keep in mind that TV Lines is what mainly controls the price of the CCTV camera.

3- The Resolution of which the DVR does display and record. which is the original dimensions in pixels of the displayed or recorded video Such as 160x120, 320x240 and 640x480 and the higher is the better.

4- The HDD capacity of the CCTV DVR. which basically means the number of recorded previous days of video that the DVR will keep before recycling. most CCTV systems by default record video based on motion which means if there is no motion there is no recording because practically it will be a still image rather than video. the average for a 4 camera system is between 160GB and 250GB and the higher the more days of recorded video (motion) your DVR system keep.

5- Remote capability. Now a days a standard CCTV camera systems are remote view capable. which means you can view your cameras remotely and virtually from anywhere in the world using the internet using internet explorer or using a remote client that is installed on the PC your accessing the DVR from.

6- Back up and recovery compatibility. CCTV camera systems give you the ability to back up desired video period either on CD-R, DVD-R or USB storage including USB flash drives. Making it easy to export video to other devices for many various reasons. for example making a copy for the police or the insurance company.