This document provides an overview of how living things are classified. It explains that living things are divided into two large groups: animals and plants. Animals are further divided into vertebrates and invertebrates. Vertebrates are animals with backbones and include five groups: amphibians, birds, fish, mammals, and reptiles. Each group is described. Invertebrates do not have backbones and include eight groups: molluscs, flatworms, annelids, roundworms, sponges, echinoderms, cnidarians, and arthropods. Details are provided on the characteristics of each invertebrate group.