Abiotic
Non-living or physical factor in an ecosystem e.g temperature, pH, wind, light intensity
Biotic
Living or biological factor in an ecosystem e.g food competition
Community
Population of all different species living in the same habitat
Ecosystem
Interaction between a community of living organisms and the non-living factors in the environment
Population
Organisms of one species in the same habitat that can potentially interbreed
Species
Organisms which can reproduce and make living, fertile offspring
Ecology
The study of the relationships between organisms and their environment