Short answers, pulled from the story.
Street Fighter II: Champion Edition is a 1992 video game released as Street Fighter II Dash in Japan that fundamentally altered the fighting game genre by making the final four computer-controlled opponents playable. The game features four Grand Masters, Balrog, Vega, Sagat, and M. Bison, who were previously insurmountable bosses but became viable competitors in competitive play.
Street Fighter II: Champion Edition was released in the spring of 1992, with specific console versions following later such as the PC Engine version on the 12th of June 1993 and the Genesis version on the 27th of September 1993 in North America. The game dominated arcade charts in May 1992 and held the number one spot on RePlay's coin-op earnings chart through September 1992.
Street Fighter II: Champion Edition generated over 2.3 billion US dollars in gross revenue worldwide, securing its place as one of the top three highest-grossing arcade games of all time. In Japan alone, 140,000 arcade hardware units were sold at 1,000,000 yen each, generating 22.4 billion yen in hardware sales revenue which equated to approximately 182 million US dollars at the time.
Street Fighter II: Champion Edition allows players to control the four Grand Masters Balrog, Vega, Sagat, and M. Bison in addition to the original eight fighters. The game also introduced mirror matches where any character can face a clone of themselves distinguished by alternate color schemes and blue name tags.
Street Fighter II: Champion Edition appeared on multiple platforms including the PC Engine, Genesis, X68000, Master System, Sega Saturn, and PlayStation with releases ranging from 1993 to 1998. The game was later re-released on the Wii Virtual Console, the Sega Genesis Mini, and the Nintendo Classics service.