-Phylum is a taxonomic ranking that comes third in the hierarchy of classification, after domain and kingdom. Organisms in a phylum share a set a characteristics that distinguishes them from organisms in another phylum.
-The phylum group is then divided into even smaller groups, known as classes. For example, phylum Chordata , which is split up into classes, mammalia, Fishes, Aves, Amphibia and Reptilia.
