An ecosystem is a community of interacting organisms and their environment. It refers to an area (of any size) where living things interact with each other as well as non-living things like soil, water, and air. Organisms can only survive in an ecosystem when their specific needs are met. If an organism’s needs are not met, one of three things happens: (1) it adapts over many generations, (2) it moves to a different ecosystem, or (3) it does not survive. An ecosystem is in balance when all needs are met for all components. If something changes, the ecosystem may become unbalanced.