A baseball is harder and more round, so it needs a glove with a bigger surface area that can cover more of the ball. A softball is bigger and slower than a baseball, so it doesn't travel as far when hit and doesn't need as much coverage on the glove. That's why softball gloves are smaller - to give you better control over the ball. Baseball and softball gloves have different sizes because they are meant for different sports. Baseball gloves are typically larger so that they can better grip the ball, while softball gloves are typically smaller so that players can catch the ball more easily.