The fastest growing segment of the security video market is the network or IP camera. And the fastest growing IP camera technologies are HD and megapixel. Therefore, it is important to understand the difference between standard definition (SD), high definition (HD), and megapixel cameras.
Analog (coax) camera resolution is measured in horizontal lines and is referred to as TV Lines (TVL). The typical high-resolution analog camera is 540 to 600 TVL. Many SD IP cameras are derived from these analog cameras and have the same resolution. However, IP camera performance is not measured by resolution, but rather, by pixel count.