A cathode ray tube television, or CRT TV, is an older type of television that uses a large glass tube to display images. Inside the tube, electrons are emitted from a cathode and directed towards a phosphorescent screen. When these electrons hit the screen, they create light and form the images we see. CRT TVs were popular from the mid-20th century until the early 2000s, known for their bulky design and deep screens. They have largely been replaced by newer technologies like LCD and LED displays, which are thinner and more energy-efficient.