Biological Classification
So… how do we keep track of all the millions of species of plants and animals and other living things on the planet? We use biological classification to classify every living thing! Read more about it…
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDivers_class.html
http://www.wisegeek.com/what-is-biological-classification.htm