Mode 7 is the Super Nintendo's built in pseudo-3D mode. Mode 7 can take any flat surface and rotate it in any direction, and allow it to be viewed from any angle. Besides the world maps on many an RPG, Mode 7 also saw heavy use for backgrounds in racing games. Street Fighter II even used Mode 7 to generate the floor (although the effect is rather subtle).
Mode 7 served many a developer for years on the SNES, but eventually they needed something more. The SuperFX chip was developed to allow for realtime 3D effects on things other than just flat surfaces.