What is Chordata?

Answer

a chordata is a fresh water lobster

"Chordata" is a phylum of animals having a notochord. Generally, the notochord exists at some stage of the animal's development, but it is often replaced with a spinal column as the animal progresses beyond the embryo stage.

A member of the phylum Chordata is called a chordate. You are one. Lobsters are not.

See http://en.wikipedia.org/wiki/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.