If you are a right-handed player, and your opponent returns a ball directly towards your body, your tendency is to step to your left and hit the ball from the right side of your body.
If you are a left-handed player, and your opponent returns a point directly towards your body, you naturally step to you right side and hit the ball from the left side of your body.
Because the forehand stroke is a sort of a natural stroke, this stroke is performed more by players in tennis matches compared to the other tennis strokes.