SLO stands for Slow Pitch Softball, a variation of the traditional game of softball. It is a team sport in which players throw a ball to each other and try to hit it with a bat. The main difference between slow pitch and fast pitch softball is that in slow pitch, the ball is thrown in an arc, while in fast pitch, the ball is thrown in a straight line. Slow pitch softball is typically played on a larger field than fast pitch, and the rules are slightly different. Slow pitch softball is a popular recreational sport, and is often played in parks and other outdoor areas.