A CRT monitor, or Cathode Ray Tube monitor, is an older type of display device that uses electron beams to create images on a phosphorescent screen. These monitors are bulky and heavy due to the glass tube that houses the components. They were widely used in the past for computers and televisions before the advent of more modern display technologies. Despite their size, CRT monitors offered good color reproduction and fast response times, making them popular for gaming and graphic design. However, they have largely been replaced by LCD and LED monitors, which are thinner, lighter, and more energy-efficient.