LCD connections: analog vs. digital

LCD connections: analog vs. digital
There are two major types of computer monitors: CRTs, which are based on the same 100-year-old cathode-ray-tube technology as the first television, and LCDs, which are based on newer, liquid-crystal technology. Although CRT monitors are still optimum for some tasks, LCDs look slicker, take up less desk space, and can offer sharper image quality, and as a result, they have begun to dominate the market. Most CRTs offer only an analog connection, but more and more LCDs offer both digital and analog inputs. Which one should you use?

Let's take a step back. A CRT, or cathode-ray tube, monitor is an inherently analog device, while computers are purely digital devices. How does a twentieth-century analog appliance talk to a twenty-first-century digital machine?

Analog (VGA) input
They do so via a graphics card (also called a video card). Most computers have at least one analog input, which is sometimes labeled VGA (for video graphics array) or D-SUB, on the back of the computer.

The graphics card converts the computer's digital signal to an analog one, which it conducts to the monitor via an analog cable. Without getting into too much detail, the CRT monitor takes the analog signal and uses electron guns to manipulate phosphors and, well, it turns the signal into an image.