Many years ago before LCD Televisions were invented, our TV screens used to be made up of horizontal lines, 405 of them in the very early days becoming 625 later. These were known as television lines in the trade, TVL for short. As each horizontal line played a part in making up the picture, it followed that the more lines you had, created a smoother, more detailed image. This is what we now call a high resolution image.

Whilst these type of television sets have long since gone CCTV cameras using the same technology still live on and occupy over 90 percent of the CCTV market. It still follows that the more Television lines (TVL) you have on your CCTV camera, the better and more detailed the picture and therefore the higher the resolution.

Televisions have now been digitised and the picture is no longer made up of lines but pixels. In easy to understand language a pixel is an individual square and many thousands of them fill the screen. As followed with TVL, the more pixels you have the better and more detailed the image, in other words the higher the resolution.