When learning about ecology, it is helpful to have an understanding of basic ecological terminology. So, let's review some key terminology!
A species is a group of organisms that are able to interbreed and have viable, fertile offspring. Thus, to be considered a species, offspring must have the capacity to reproduce. For example, all dog breeds are of the same species - a husky and golden retriever (different breeds but both dog species) can mate and produce viable, fertile offspring.
An organism’s habitat is the type of place an organism lives in. It includes all other organisms present, as well as the physical and chemical aspects of the environment. For example, the habitat of the bacteria of H. pylori is the digestive system of a human; the habitat of a pet lizard is its tank.
A population is a group of organisms of a specific species that live in a given location. An example is all of the koi fish living in a pond or all of the oak trees in a forest.
An ecological community encompasses all of the populations living in a certain area where the different species interact.