CRT

Cathode Ray Tube (CRT) is a vacuum tube containing an electron gun (a source of electrons) and a fluorescent screen, with internal or external means to accelerate and deflect the electron beam, used to form images in the form of light emitted from the fluorescent screen. CRT is used (among other applications) as a video display for televisions and computer monitors.

The CRT uses an evacuated glass envelope which is large, deep, heavy, and relatively fragile. Display technologies without these disadvantages, such as flat plasma screens, liquid crystal displays (LCD), DLP, OLED displays have replaced CRTs in many applications and are becoming increasingly common as costs decline.