Air-Independent Propulsion (AIP) is a technology that allows submarines to operate underwater without needing to surface for air. This system enables submarines to remain submerged for extended periods, enhancing their stealth and operational capabilities. AIP systems can use various methods, including fuel cells, Stirling engines, or closed-cycle diesel engines, to generate power without atmospheric oxygen. AIP is particularly beneficial for naval forces as it improves the effectiveness of submarine warfare. By reducing the need to surface, submarines can avoid detection and remain hidden from enemy forces. This technology represents a significant advancement in underwater military operations.