An ecosystem is that it is a community or group of living organisms that live in and interact with each other in a specific environment.

Example: a wetland in East Africa

A biome is an area of the planet that can be classified according to the plants and animals that live in it.

Example: grassland

The biosphere represents the totality of all things on Earth, including their interactions. The biosphere includes all ecosystems on Earth and how they interact together.

Example: the Earth

The community level focuses on the relationship between different species in a community. Predator and prey relationships play a large role in community-level analyses.

Example: the elephant and the crocodile

A population contains a group of individual organisms of the same species and living in a specific geographic area -- which interact with one another.

Example: a parade of elephants

The first level of the ecological hierarchy. This level examines how one organism interacts with its environment.

Example: an elephant