CCTV cameras are available in a wide variety of shapes & sizes with a great many different features and functions. In general, there are 3 types of CCTV cameras:

• Box camera - traditional style camera consisting of a rectangular box with a lens attached
• Dome camera - available as fixed or with Pan Tilt & Zoom (PTZ) features
• IP network cameras - digital cameras that work over computer networks (both box and dome cameras can be network IP cameras)

Apart from obvious differences in shape or style, most cameras usually feature similar specifications. Power is normally supplied over 12vDC or 24vAC or 48vDC (POE) voltage although 120vAC and 240vAC cameras are also available. Quality of images are measured in TVL (tv lines), where the higher the number, the higher the quality or resolution of the image. Lenses affect the distance and angle of the image. Lenses are measured in mm with fixed lenses and varifocal lenses available for customised field of view. Images captured by cameras are subject to lighting conditions which can affect image quality. Light levels are measured in Lux, the lower the number the better the camera can see in the dark. Infra Red sensitive cameras can view images in very low light and aided with IR light can see in complete darkness. These IR cameras are usually refererred to as night vision cameras.

IP cameras work on the same principles as the description above. However, the main difference is that the video is processed within the camera, thus reducing the load on recording devices to convert the image to digital format. Added to this, IP cameras can use regular network cable for transmitting video making it easier to install and reduce the number of cables required. Another benefit is that IP cameras can be distributed over a wide area making them more accessible than regular cameras, although DVRs with traditional cameras connected to them can easily be connected and distributed in a similar manner.