There are many different types of CCTV systems available—wired and wireless—and their modes of operation vary; however, the basic components are in essence the same: a CCTV camera, a CCTV monitor & a Digital Video Recorder (DVR).

The images collected are sent to a CCTV monitor and recorded on a DVR hardrive. The size of the hardrive determines how long the images are stored for, typically a 2TB hardrive with 16 cameras and motion sensing will store upto two weeks of data

This is particularly useful for unmanned systems. The recorded information can be stored and/or reviewed by those who have access to the recordings at their convenience. Many of the latest DVRs also have network connections so that saved and live footage can be accessed remotely via a PC or their smartphone over the internet.