Buddy breathing is a term used in scuba diving to describe the act of sharing a single regulator with a diving partner in case of an emergency. However, there are other terms used to refer to this practice, including air sharing, alternate air source, and octopus sharing. Air sharing is a commonly used term, as it accurately describes the act of exchanging air between divers. The term alternate air source refers to the backup regulator that is carried by each diver, while octopus sharing refers to the octopus regulator, which is a type of alternate air source designed specifically for emergency situations. Regardless of the term used, buddy breathing is an essential safety practice that all scuba divers should be proficient in.