Configuration in this case means what appears on the face of the target. Some targets are round with a round bullseye, some are square with square aiming points, some are shaped like animals, some are shaped like a human torso and head. Some depict bad guys pointing guns at you, with aiming points located in the spots where you would shoot to stop an attack, while some are even designed as games where you score points by hitting specified spots. Pick whatever suits your fancy at the moment. And remember, it's always more fun to have an assortment since you never know what your shooting partners might prefer.