The palm is the inner surface of the hand from the wrist to the base of the fingers. For many anatomical cases, the inner surface of the fingers can also be considered part of the palm because it shares the same anatomical properties.
The skin of the palm, the inside of the fingers, the fingertips, the soles of the feet and the underside of the toes is notably different from the rest of the skin of the human body in the following respects:
In shaking hands, the palms of two persons touch another. In clapping the hands (e.g. for applause) and in Christian-style prayer, a person's left and right palm make contact. In some parts of Asia, the palms are held together in greetings like the Thai greeting wai and its Indian correspondent, namaste.
The palm is also used for corporal punishment. In face-slapping and similar ad-hoc punishments, the slap is usually delivered with the palm. In hand-spanking, it is the palm that makes contact with the buttocks (and has to absorb the impact on the spanker's side).
Finally, the palm can also be the recipient of corporal punishment: see striking the hand for more on this.