A hand is the part of the body at the end of an arm. Most humans have two hands. Each hand usually has four fingers and a thumb. On the inside of the hand is the palm. The five bones inside this part of the hand are called metacarpals. The wrist connects the hand to the arm.
When the fingers are all bent tightly, the hand forms a fist. The joints that are the hardest part of the fist are called knuckles. Many other animals, especially other primates, have hands that can hold things. Human hands can do things other hands cannot.