In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between the elbow and the radiocarpal joint (wrist joint) is known as the forearm or "lower" arm, and the extremity beyond the wrist is the hand.

By anatomical definitions, the bones, ligaments and skeletal muscles of the shoulder girdle, as well as the axilla between them, is considered parts of the upper limb, and thus also components of the arm. The Latin term brachium, which serves as a root word for naming many anatomical structures, may refer to either the upper limb as a whole or to the upper arm on its own.