Closed-circuit television camera

[2] Video cameras are either analogue or digital, which means that they work on the basis of sending analogue or digital signals to a storage device such as a video tape recorder or desktop computer or laptop computer.

Such a device is similar in functionality to a PC with a capture card and appropriate video recording software.

Unlike PCs, most DVRs designed for CCTV purposes are embedded devices that require less maintenance and simpler setup than a PC-based solution, for a medium to a large number of analogue cameras.

Some DVRs also allow digital broadcasting of the video signal, thus acting like a network camera.

These cameras do not require a video capture card because they work using a digital signal which can be saved directly to a computer.

However, in any situation where standard-definition video cameras are used, the quality is going to be poor because the maximum pixel resolution of the image chips in most of these devices is 320,000 pixels (analogue quality is measured in TV lines but the results are the same); they generally capture horizontal and vertical fields of lines and blend them together to make a single frame; the maximum frame rate is normally 30 frames per second.

Multi-megapixel IP-CCTV cameras can capture video images at resolutions of several megapixels.