"S" is supposed to mean sport.
*borrows Ryan Braun's soapbox*
For example, I driving a 2005 MINI Cooper S. The standard MINI engine is a 1.6L 4 cylinder that makes, 110hp. The Cooper S makes 165 due to the supercharger put on top of the standard engine. It also has a different suspension that makes it more capable in the twisty bits. Sport(y).
The Corolla has some plastic shit bolted on and at last check has rear drum brakes. It is essentially an appearance package. Not sport(y).
*steps off soap box, flips Braun the bird, and exits stage left*