What is the phylum chordata?

Chordata is the phylum of animals that have a number of features in common, but most notably a notochord (which is called a spinal cord in humans because we have a backbone, a spine, through which it is routed). All the vertebrates (animals with a backbone) are grouped within this phylum. The chordates also include a number of other animals that do not have a backbone, but do have the notochord.