Why do you use the inside of your foot in soccer?

Players need the traction to accelerate, stop, turn and otherwise maneuver during the course of the game. Some sort of cleats on the boots (shoes) facilitate this. And that's why those shoes were developed and are worn. However, it is important to note that cleated boots or shoes are not required under the Laws of the Game, only that any cleats, it worn, must not be dangerous to anyone else on the pitch.