CRTs, or cathode ray tubes, are devices used in older television sets and computer monitors to display images. They work by firing electrons onto a phosphorescent screen, which lights up to create pictures. The technology was widely used before the advent of flat-screen displays like LCD and LED. Despite being largely replaced, CRTs were known for their deep colors and fast response times. They are bulky and heavy compared to modern screens, making them less convenient for everyday use. However, some enthusiasts still appreciate CRTs for their unique visual qualities, especially in retro gaming and vintage media.