The neat thing about TV is that it works at all. Television and movies take advantage of something called “persistence of vision.” See, the average person blinks about 15 times a minute. You don’t notice it because your brain is programmed not to. Your brain automatically blends information so that when it’s unexpectedly dark (like when you blink) your brain just holds the last image you see in your mind.
Another little trick your mind plays on you is that since you can’t get perfect detail on anything more than just a few inches away, any gaps get filled in by your imagination, and colors and details that you can’t see perfectly get blurred out.
TV and movies use these properties which evolution has bestowed upon you to make it look like a series of dots are actually a picture, and to make it look like a single moving line is actually a full frame of video.
I could go into incredibly long detail on how TVs work, but it’s so much easier if you actually take a look at the video below. It uses a slow motion camera, extremely close to the screen, to actually show an old tube TV as well as a modern TV, in action.