The term 'SCUBA' is an acronym for 'Self-Contained Underwater Breathing Apparatus with a Harness and Flippers'. It is a type of equipment used by divers to explore underwater environments. It consists of a breathing apparatus, a harness to secure the apparatus to the diver, and flippers to help the diver move through the water. SCUBA is a popular activity among recreational divers and is also used in scientific research and other professional activities.