What are the Two main kinds of animals?

The two main kinds of animals are vertebrates and invertebrates. Vertebrates have a backbone and include groups such as mammals, birds, reptiles, amphibians, and fish. Invertebrates, on the other hand, lack a backbone and encompass a diverse range of animals, including insects, arachnids, mollusks, and crustaceans. These classifications help scientists understand the vast diversity and evolutionary relationships among animal species.