Q. Explain Cathode-ray tube?

While the CRT display is one of the oldest, it still remains one of the most popular display technologies. The raster-scanned display devices work similarly to commercial television sets, whereas graphics display devices use different technologies to achieve extremely high resolution. A CRT video signal has only two levels, with a 0 level causing a dark spot and a 1 level causing a bright spot. The appropriate combination of 1s and 0s displays data on a CRT screen, with each character displayed by dot-matrix displays, typically in 5 × 7or7 × 9 display fonts.