GROUNDED SYSTEM

Short for Cathode Ray Tube, a CRT is the electron beams in a monitor moving across your screen either interlaced or non-interlaced, hitting phosphor dots inside the glass tube.

In the CRT are three electron guns: red, green, and blue. Each of these guns streams a steady flow of electrons, left to right, for each line of your monitor. As the electrons hit the phosphors on the CRT, the phosphor will glow certain intensities. As a new line begins, the guns will then begin at the left and continue right. These guns will repeat this process sometimes thousands of times until the screen is completely drawn line by line.

Once the phosphors on the CRT are hit with an electron, they only glow for a short time. Because of this, the CRT must be refreshed, which means the process will be repeated as explained above. If the video card's refresh rate is not set high enough, you may see flickers or a noticeable steady line scrolling from top to bottom of the screen.