A "hominin" refers to a group of species that includes modern humans, their ancestors, and other extinct relatives. This classification is part of the broader family of Hominidae, which also includes great apes like chimpanzees and gorillas. Hominins are characterized by traits such as bipedalism, which is the ability to walk on two legs, and larger brain sizes compared to other primates. The study of hominins helps scientists understand human evolution and the development of unique human traits. Key hominin species include Australopithecus, Homo habilis, and Homo sapiens. By examining fossils and archaeological evidence, researchers can trace the physical and behavioral changes that have occurred over millions of years.