A cathode ray tube (CRT) is a vacuum tube that uses electrons to create images on a screen. It was commonly used in older televisions and computer monitors.
In a cathode ray tube, a heated filament emits electrons that are accelerated towards a positively charged screen. The electrons are then deflected by magnetic fields to create images on the screen.
Cathode ray tubes were known for their high image quality and fast response time. They were also relatively inexpensive to produce.
Cathode ray tubes have been largely replaced by newer technologies such as LCD and LED screens. These newer technologies offer better image quality and are more energy efficient.
There have been concerns about the electromagnetic radiation emitted by cathode ray tubes, but the levels are typically considered safe. However, prolonged exposure to these screens may cause eye strain and fatigue.