There are TWO types of "RGB" (Red Green Blue). VIDEO RGB is otherwise known as COMPONENT, and is connected by three RCA-type connectors, (colored Red, Green and Blue). DATA RGB is your standard computer-monitor connector, otherwise known as 15-pin (or sometimes, errantly, VGA, which is explained more below).
RGB – When computers first came out, they had a resolution referred to as CGA, Centered Graphics Array, and (I think) the resolution was 288 X 166. They quickly advanced to EGA, then VGA, then SVGA (super VGA), then XGA, SXGA (super XGA), UXGA, (Ultra XGA) WXGA so on and so forth. When monitors first really started being popular, the standard was VGA, so everyone referred to it as a VGA cable. Some people still do, although the actual resolution might be much higher, like SXGA. Just make sure when someone says: RGB" are they referring to the VIDEO- COMPONENT Red Green Blue, with the three colored RCA connectors, or the DATA – 15 Pin (VGA standard computer monitor cable).