Animal species are groups of living organisms that share common characteristics and can interbreed to produce fertile offspring. Each species is classified based on traits such as physical appearance, behavior, and genetic makeup. The scientific study of these classifications is known as taxonomy. There are millions of animal species on Earth, ranging from tiny insects to large mammals. They inhabit various environments, including forests, oceans, and deserts. Understanding animal species is crucial for biodiversity conservation and helps scientists monitor ecosystem health and the impacts of climate change.