Short for Game Boy Color, the third generation of Nintendo's line of popular handheld gaming systems. The progression went like:

Game Boy: This large white box was the front runner in portable gaming systems. It took 4AA batteries, and did not last very long on a charge. It had a huge library of great titles, such as Metroid 2, the always popular Tetris, many good offerings from Square, etc.

Game Boy Pocket: This lighter and more compact (thus the "Pocket" inclusion in the title), took the Game Boy, upped it's battery life, moving to a two AAA battery scheme, and reduced the blur associated with the original Game Boy. The link cable size was reduced, and needed an adaptor to work with the older model. Still 100% compatible. The unit itself was available in several different colors.

Game Boy Color: This most recent offering added improved clarity, the ability to color-ize old games (thus giving the four-color scheme contrast), and the ability to run newer full color games. This was an amazing leap for the gameboy. The sound was still as good as ever, the non-color games are still fully supported, and the battery life got better (the battery size was increased to AA). The link cable was virutally removed, as an efficient IR connection now lies in it's place for faster and easier connections. There is still a port for backwards compatibility with older cabling systems. The power adapter has also moved to a proprietary unit.

The game boy has sold millions of units, and has been described and Nintendo's silent success, as it has stood the test of time, and competitors.