What is the difference between somebody that is in a coma vs under anesthetic vs sleeping deep?

Big difference: Persons in a coma that is not induced by medication typically have damage to a part of their brain that governs sleep-wake cycles called the reticular activating system. They do not respond to the natural processes that wake us up after sleep. They cannot be awakened by loud noises or change in light. There are different levels of coma. Even people sleeping deeply have a normal nervous system.