As part of the fourth generation of video game consoles, the Sega CD was released in Japan in 1991, North America in 1992 and in Europe and other regions in 1993. The device adds a CD-ROM drive to the Mega Drive console, allowing the user to play CD-based games and providing additional hardware functionality. Other benefits of the add-on include a faster central processing unit and graphic enhancements. It can also play audio CDs and CD+G discs. The main benefit of the new add-on's technology was its larger disc space, allowing for larger games to be developed. This would manifest itself in the form of full motion video (FMV) games.
By the end of 1994, the add-on had sold approximately 2.7 million units worldwide. In 1995, it was announced that Sega's support would shift away from the Mega Drive and Sega CD to focus on its new console, the Sega Saturn, and the add-on itself was officially discontinued in 1996.
Retrospective reception to the add-on is mixed, praising the Sega CD for its individual offerings and additions to the Mega Drive's functions, but criticizing the game library as a whole for its lack of depth and low value for money, as well as issues with how the add-on was supported by Sega.