Buoyancy control refers to the ability to manage an object's floatation in a fluid, such as water. It is essential for activities like diving and swimming, where maintaining a desired depth is crucial. By adjusting the amount of air in a buoyancy control device or changing body position, individuals can rise, sink, or remain at a specific depth. In diving, proper buoyancy control helps prevent rapid ascents or descents, which can be dangerous. Divers use techniques like breath control and equipment adjustments to achieve neutral buoyancy, allowing them to move effortlessly underwater while conserving energy and minimizing the risk of injury.