Hands
Source Player Core pg. 254
Some weapons require one hand to wield, and others require two. Weapons requiring two hands typically deal more damage. Some one-handed weapons have the two-hand trait, causing them to deal a different size of weapon damage die when used in two hands. In addition, some abilities require you to wield a weapon in two hands. You meet this requirement while holding the weapon in two hands, even if it doesn't require two hands or have the two-hand trait.
Multi-Armed Characters: Characters that have more than two hands, like kasathas, can hold more items and weapons than typically expected. Performing actions with multiple pairs of arms concurrently is a challenge and can't be done without intensive training. You must designate a pair of hands as your active hands. You can change this designation from one pair of hands to another by taking the Switch Hands action. Some feats can adjust your skill with multiple hands. You can only attack with weapons wielded in your active hands.
Multi-Armed Characters: Characters that have more than two hands, like kasathas, can hold more items and weapons than typically expected. Performing actions with multiple pairs of arms concurrently is a challenge and can't be done without intensive training. You must designate a pair of hands as your active hands. You can change this designation from one pair of hands to another by taking the Switch Hands action. Some feats can adjust your skill with multiple hands. You can only attack with weapons wielded in your active hands.