A light weapon is a weapon that is of a smaller weapon size than the creature using it. Natural weapons and unarmed strikes are also considered light weapons. These weapons can only be wielded in one hand, so a creature will only add 1x their strength modifier (or intelligence modifier if they have Combat Insight) to damage if they are wielding a light weapon with their off-hand empty. If a light weapon is wielded in a creature's off-hand, the penalty to attack for each hand is reduced by 2. Light weapons can be used with Weapon Finesse. However, Weapon Finesse uses the list of light weapons for medium creatures for all creatures.
Note: Melee Touch attacks are not affected by this feat, even if a light weapon is equipped.