This document provides an overview of closed-circuit television (CCTV) cameras and video surveillance systems. It discusses the different types of CCTV cameras, including analog, digital, and network cameras. It explains how CCTV cameras work by sending video images and audio data to a monitor or storage device for live or recorded viewing. The purpose of CCTV systems is to act as a deterrent against unlawful activity and to document any crimes that occur through video recordings. Various CCTV camera technologies are also outlined such as bullet cameras, dome cameras, and pan tilt zoom cameras.