Super Nintendo NES SystemThe NES was still going fairly strong in the late 80s and early 90s, but with its ancient 8-bit processor, the industry was quickly surpassing it with flashy, faster 16-bit systems. The most notable of these was the Japanese console, Sega's MegaDrive, which was released in the US under a new package and named Genesis. Nintendo had to do something fast or they would be out of the gaming forefront forever. The answer was to release the Super Famicom into the United States. They called it the Super Nintendo and it was released in 1991 to rave reviews... but they were too late.
Sega's Genesis had almost completely saturated the market, with a huge catalog of quality games and third party developers. It wasn't until 1997 - six years later - that the Super Nintendo was finally able to surpass the Genesis in sales; and this was after Sega stopped producing and supporting their system.
So it was between two competing systems in the United States: Sega Genesis and Super Nintendo. But it wasn't all about competition for the same market - in fact, those two systems, though both technologically similar, are for two different markets. While Genesis focused on sports and arcade games, Super Nintendo got its sales from a much younger audience; mainly those longing for adventure and platform. Genesis utilized its processor for better sound, Super Nintendo used it for better graphics. They were two differently marketed gaming consoles.