The following common terms can be used to describe living things in their environment:
- environment - all the conditions that surround a living organism
- habitat - the place where an organism lives
- population - all the members of a single species that live in a habitat
- community - all the populations of different organisms that live together in a habitat
- ecosystem - a community and the habitat in which it lives
Biodiversity is a measure of the variety of different species living in a habitat. The greater the number of different species in a habitat, the greater its biodiversity.