Excretion is the process of removing wastes and excess water from the body. It is an essential process in all living things. It is one of the major ways the human body maintains homeostasis. It also h...Excretion is the process of removing wastes and excess water from the body. It is an essential process in all living things. It is one of the major ways the human body maintains homeostasis. It also helps prevent damage to the body. Wastes include by-products of metabolism, some of which are toxic, and other non-useful materials, such as used up and broken down components.