Your habitat is the environment you are accustomed to living in. Zoos usually try to mimic the habitats of the animals they keep, housing bats in a nocturnal house and monkeys in a cage with trees to climb and swing from.
The origins of habitat aren't exactly what you would expect. The word goes back to the Latin habitare meaning "to live or dwell," which itself goes back to habere meaning "to have or own." It seems logical that if you own a place, it is your home. Habitat is usually used with animals and plants that live in and are adapted to a specific environment. In nature, orchids and banana plants live in a warm, humid habitat.