Palmistry, Chirology or Cheirology is the study of the hand.
It involves looking at all aspects of the hand - handshape, finger length and shape, the thumb, nails, knuckles, skin texture, flexibility, fingerprints, and the patterns, lines and markings on the palm - assessing and interpreting these features, like putting together the pieces of a jigsaw, to give an in-depth view of all aspects of the individual.