'CP' System stand for 'Capcom Play' System.
The earlier Capcom system board, the original "CP System
" (or CPS-1), while successful, was very vulnerable to bootleggers making unauthorized copies of the games. In order to rectify the situation, Capcom took the CP System hardware (with QSound) with minimal changes and employed encryption on the program ROMs to prevent software piracy. Due to the encryption, the system was never bootlegged until unencrypted program data became available.
The CPS-2 Game board (known as the 'B board') comes in six different colors. It was thought that these colors matched up to the language used in game but on getting all the different colored 'A' boards it's clear to see that the color denotes the country of release.
Blue: U.S.A., Canada, and Europe
Orange: South America
Yellow: All (Rent version)
The first game produced on this system was "Super Street Fighter II The New Challengers". The last game (so far) is "Hyper Street Fighter II : The Anniversary Edition". All up, around 50 unique games were developed on CPS2 hardware, with dozens of releases in different regions, totaling over 170 variations. Over the years Capcom have produced a lot of games using the same theme, making numerous spin-offs of their titles with varying subtitles in an effort to prolong the life of the aging CPS-2 hardware (one would assume).