Slow pitch softball is the version of softball games where pitchers pitch the ball slowly in a lobbing style as opposed to fast pitch softball where a pitcher is allowed to wind up their arm to pitch the ball fast.
In slow pitch softball the ball is typically anywhere from 12 to 14 inches circumference as opposed to fast pitch where the ball is almost half the size.
Slow pitch and fast pitch bats are pretty much the same, however, there are manufacturers that make specialty bats for both types of softball games.
In some leagues you may start your at bat with 1 foul and 1 strike.