Homeostasis is a mechanism that is managed by the body of an organism in order to maintain the balance of its physiological system. In this regard, the body is doing coordinated response to the area (or parts) where the normal distribution of work or function is disturbed. In other terms, it can be defined as maintaining the equilibrium of the body despite of factors that affects it.
In higher animals like mammals, the main system that is responsible for the maintenance of the system is the nervous system, specifically the autonomic nervous system. This system overall controls the production of hormones, temperature maintenance, regulation of blood and water levels and many more. Other systems and organs that are directly involved in homeostasis are the liver, kidneys, the brain (hypothalamus), and the endocrine system.