This page describes the basics of the television signal, how to analyze it on a Waveform Monitor or Vectorscope and how to set up a monitor to color bars. In North America the video signal is a standard, called NTSC, and is not the same as computer, or RGB video. To maintain consistent image quality, it is important to use only properly calibrated monitors to evaluate and test the video picture.
Video is a linear medium like audio, unlike photography or film.
A film camera captures the entire frame of a picture in a single instant. But video was originally designed to be transmitted over the air. Images must be broken up and transmitted or recorded as a series of lines, one after the other. At any given millisecond, the video image is actually just a dot speeding across the face of the monitor glass. Television is also primarily an analog medium.