Biologists have a way of classifying everything. By classifying, you put things into groups that have similar characteristics. This is sorting which is like the science of taxonomy. Taxonomy (pronounced tacks-on-o-me) is like building a family tree. Another way to look at it is like a pyramid.
The further down the pyramid you go, the more of us there are in each division or block. We are all related, but there are body parts (which you'll learn about) that either make us the same or different from our cousins down the pyramid.