vertebrates
humans, chordates are anything with a spine.
Chordates are a group of animals which include vertebrates (animals having a spinal column), so yes, birds are chordates.
adult tunicate
all vertebrates are chordates because vertebrates are the sub- group of phylum chordates and also it follow one of the important feature of the chordates i.e. presence of notochord whereas all chordates are not vertebrates because some chordates are cephalochordates, urochordates.
Chordates
Chordates are that group of animals having some form of a spinal column (which include the vertebrates).
Well, no they don't... There's a group of chordates called Agnatha which basically contains all the jawless chordates. And there are obviously limbless chordates present, the fishes and the snakes being the most well-known of the examples...
The class of chordates that have a dual life are amphibians. This group includes frogs, toads, newts, and salamanders,
Chordates.
Lower chordates
Vertebrates are a subgroup of the chordates, meaning that all vertebrates are chordates, but not all chordates are vertebrates. Vertebrates are distinguished from other chordates by having backbones or spinal columns.All vertebrates have muscular systems that mostly consist of paired masses, as well as a central nervous system which is partly located inside the backbone (if one is present). The defining characteristic of a vertebrate is considered the backbone or spinal cord, a brain case, and an internal skeleton, but the latter is not true for lampreys, and the former is arguably present in some other chordates. Rather, all vertebrates are most easily distinguished from all other chordates by having a clearly identifiable head. Sensory organs--especially eyes--are concentrated at the foreend of the body, and there is pronounced cephalization.
mammals/birds/and chordates