Vertebrates are distinguished from invertebrates by the presence of a vertebral column, or backbone, which is part of an internal skeleton made of bone or cartilage. This feature offers structural support and protection for the spinal cord, a key component of the central nervous system. Vertebrates include groups such as mammals, birds, reptiles, amphibians, and fish. Conversely, invertebrates lack this backbone and represent a diverse range of organisms, including arthropods, mollusks, and cnidarians, showcasing different body plans and adaptations.