As with many other electronics-related topics, video display technology is rife with complicated acronyms that can confuse a standard user. The difference between VGA and RGB is one such topic.
RGB stands for “red, green, blue” and refers to a video signal that transfers each of the three standard colors separately. By contrast, a composite video signal mixes the three colors together. Non-LCD computer monitors use RGB signals.
Video Graphics Array is a PC display system originally developed by IBM that replaced earlier graphics standards. Because VGA uses an analog signal while the older systems used a digital signal, a monitor designed for one of these older standards cannot use VGA.
A VGA analog signal is capable of transmitting any value within a certain range. By contrast, an RGB digital signal is limited to specific values within that range. For example, a digital signal may be able to represent any integer from one to ten, while an analog signal could also represent any fractional value between those integers.
Many other video signal standards have been developed based on VGA. Some of these include SVGA and XGA.
Analog to Digital Conversion
Digital Visual Interface is a digital interface standard designed to convert an analog signal into a digital signal and is often used when connecting a computer to a digital display device.