Protection
It acts as a barrier and protects us from bacteria, viruses and fungi.
Sensation
Sensory receptors (nerves) react to external stimuli.
Metabolic Activity
It absorbs different things such as lotions, creams and UV light from sun which generates vitamin D. It also has a detoxifying function as the body can eliminate products through the sweat.
Thermoregulation
It regulates the body temperature.