All dogs, from the giant Great Dane to the tiny Chihuahua, belong to the same species: Canis familiaris. Within that single species, there are many breeds or types. Humans produced these breeds over many generations by mating individuals with certain traits. This process is called breeding. Along with many animal species, people have also bred plants like tomatoes and bananas to create breeds with desirable traits.

Image credits: main image, Kelvin Chan.