Humans belong to the Chordata phylum, which is an animal group that includes vertebrates and some invertebrates. This phylum is characterized by having a notochord, a hollow dorsal nerve cord, pharyngeal slits, and a post-anal tail at some point in its life cycle. The Chordata phylum is divided into two subphyla: Vertebrata and Cephalochordata. Humans are part of the Vertebrata subphylum, which is further divided into five classes: Mammalia, Aves, Reptilia, Amphibia, and Pisces.