Television Lines (TVL)
The horizontal resolution produced by a camera. TVL is measured by taking a portion of an image's width equal to the height and counting the number of vertical lines displayed.
Resolution is defined as the fineness of detail that can be distinguished in an image. In CCTV cameras, resolution is measured in TV Lines (TVL). A higher number of TVL means that a camera will be able to render images with more detail. TVL is not the sole factor that determines the quality of the final output. For example, the resolution does not affect the color reproduction of the camera. The monitor and the video processing of the DVR also affect the final output.