Integumentary system is the organ system that protects the body from damages that can be made by external factors and prevention to loss of water in the body system. It also plays a big role in maintaining the temperature of the body, protection of internal tissues, plays a role in excretion and it is the site of attachments of sensory receptors.
The two main components of integumentary system are the skin and the appendages.
The skin is the largest organ in the body. It has layers which have different functions of protecting the body: the epidermis, dermis and hypodermis.
The appendages are the external body parts of an organism. This includes the hair, nail, scales, feathers and hooves.