The term "Aqualung" refers to a type of underwater breathing apparatus that allows divers to explore aquatic environments. It consists of a tank filled with compressed air, a regulator to control airflow, and a mouthpiece for inhalation. This invention revolutionized scuba diving, enabling longer and deeper dives. Originally developed in the 1940s by Jacques Cousteau and Émile Gagnan, the Aqualung made recreational diving accessible to many. It paved the way for advancements in underwater exploration and marine research, contributing significantly to our understanding of ocean ecosystems and the importance of marine conservation.