Monitors are display devices external to the computer case and connect via a cable to a port on the video card. Even though the monitor sits outside the main computer housing, it is an essential part of the complete system.
Monitors come in two major types - CRT and LCD. CRT monitors look much like old-fashioned televisions and are very deep in size. LCD monitors are much thinner, use less energy, and provide a greater graphics quality.
LCD monitors have completely obsoleted CRT monitors due to their higher quality, smaller "footprint" on the desk, and decreasing price.
Most monitors range in size from 15" to 21" or more. This size is a diagonal measurement from one corner of the screen to the other.
