The best kind of screen! They’re the normal looking ones, i.e. the tube. CRT stands for
cathode ray tube. In a CRT three
electron guns (one for red, one for green and one for blue) shoot narrow electron beams (electrons are what electricity is made of) through a tube with no air in it to the screen which is coated with phosphor, a substance which glows when electrons hit it. Magnets near the back of the tube bend the beams and make it scan across the screen like reading a book while the beams are made stronger or weaker (or turned off completely) to make different parts of the screen dark or light or different colors.
LCDs have poor color accuracy and contrast and plasma TVs get severe burn-in (meaning the screen can be ruined by static images commonly found in video games or even a TV
channel's logo at the corner of the screen). CRT is the only kind screen which actually let’s you change the resolution (not just upscaling or downscaling which makes the picture look soft). Graphics professionals still use CRT monitors because they have the best picture quality.
High definition CRT TVs always have the full
1080 lines and can change their resolution for viewing standard definition TV shows (without upscaling). Most so called
high definition LCD TVs only have
768 lines but no TV stations broadcast in 768 lines (only
480,
576, 720, or 1080 lines) so the image will always be rescaled. So what if LCDs are thinner. Unless they live in a trailer, people only get LCDs because they think they look cool.