Humans (Homo sapiens) are the only extant members of the Hominidae (great ape) family that are habitual bipeds, meaning that we walk upright on two legs. While other great apes, such as chimpanzees (Pan troglodytes), bonobos (Pan paniscus), gorillas (Gorilla gorilla), and orangutans (Pongo pygmaeus) can occasionally walk upright for short distances, it is not their primary mode of locomotion. They typically use quadrupedal locomotion, walking on all fours.
Bipedalism is a defining characteristic of human evolution and is closely linked to the development of our brain, tool use, and social behavior. Upright walking freed up our hands for other tasks, allowing for the evolution of complex tools and technologies. It also enabled us to travel longer distances and explore new environments, which contributed to the success and spread of our species.