Old-fashioned TV screens have a cathode-ray tube. This fires a single beam of electrons across the screen very quickly. The electrons hit tiny pixels one after the other, making them each glow in turn. It all happens so quickly that you don't notice the flickering.
But cathode-ray tubes are huge, hot and clunky... soooo last century. Here are this season's alternatives.
|Cross section of a cathode ray tube inside a TV set from 1994.|
Image: 10311273, Science Museum