Humans (Homo sapiens, meaning "thinking man") or modern humans are the most common and widespread species of primate, and the last surviving species of the genus Homo. They are great apes characterized by their hairlessness, bipedalism, and high intelligence. Humans have large brains, enabling more advanced cognitive skills that enable them to thrive and adapt in varied environments, develop highly complex tools, and form complex social structures and civilizations. Humans are highly social, with individual humans tending to belong to a multi-layered network of cooperating, distinct, or even competing social groups – from families and peer groups to corporations and political states. As such, social interactions between humans have established a wide variety of values, social norms, languages, and traditions (collectively termed institutions), each of which bolsters human society. Humans are also highly curious, with the desire to understand and influence phenomena having motivated humanity's development of science, technology, philosophy, mythology, religion, and other frameworks of knowledge; humans also study themselves through such domains as anthropology, social science, history, psychology, and medicine. There are estimated to be more than eight billion humans alive.
Although some scientists equate the term "humans" with all members of the genus Homo, in common usage it generally refers to Homo sapiens, the only extant member. All other members of the genus Homo, which are now extinct, are known as archaic humans, and the term "modern human" is used to distinguish Homo sapiens from archaic humans. Anatomically modern humans emerged around 300,000 years ago in Africa, evolving from Homo heidelbergensis or a similar species.