Somatotopic organization refers to the mapping of different body parts to specific areas in the brain. This organization is evident in the primary motor cortex and primary somatosensory cortex, where adjacent regions correspond to adjacent body parts. For example, the area controlling hand movements is located next to the area for arm movements. This mapping allows the brain to efficiently process sensory information and control motor functions. The concept is often illustrated by the homunculus, a visual representation showing how much brain area is dedicated to each body part, highlighting the importance of areas like the hands and face in human activity.