Classification of animals is the process of grouping together animals that have the same characteristics. Animals are classified into two major groups. One, animals with a backbone, they are called vertebrates two, animals without a backbone, they are called invertebrates, there are five major classes of vertebrates one, mammals. Two, reptiles, three, birds, four, fish, and five amphibians. In this lesson, we will cover amphibians. Examples of amphibians include the following. One, frogs, two, toads, three, nuts, and four, salamanders. The following are some characteristics of amphibians. One, they are called blooded. Two, they have a moist skin without scales. Three, they live partly in water and partly on land, and four, they lay unphotolized eggs.