Ecology is the interactions between organisms and their environments. An ecosystem contains all of the living and non-living organisms in a area. A ecosystem contains species, populations, and communities of organisms. Within each ecosystem there are several habitats, or the physical place where organisms lives. Characteristics of a habitat determine what organisms can live there. Organisms rely on their habitats in order to survive.

Energy constantly flows throughout an ecosystem. Some organisms get their energy from the sun, these are called producers. Other organisms get their energy from other organisms or producers, these are called consumers. Food chains and food webs show the eating patterns of an ecosystem.

Symbiosis refers to the relationships between different species. Competition and predation are two other ways in which organisms interact.