What is taxonomy?

the government is watching me

"I'm a brontosaurus. I'm a distinct genus from apatosauruses. The taxonomy thing isn't really real, you know. And don't forget, I'm also just a sauropod, standing in front of a paleontologist, asking him to love her."

In reference to http://www.reddit.com/r/science/comments/31qjs5/brontosaurus_is_officially_a_dinosaur_again_new/