An ecosystem is a large community of living organisms (plants, animals and microbes) at a particular place or area. The living and physical components are linked together through nutrient cycles and energy flows. Ecosystems can be of any size, but usually they are in particular places.
Each ecosystem has its own community. A terrarium community, for example, can have small animals. A desert community may have cacti, small snakes, and scorpions. A pond community can have frogs, insects, snakes, and plants, and a forest community may have rabbits, foxes and pine trees. The species in a community are divided into populations according to the particular habitats in the ecosystem.