Naval submarines are watercraft designed to operate underwater, primarily used by military forces for various missions. They can be equipped with advanced technology for surveillance, reconnaissance, and combat. Submarines are capable of launching missiles and torpedoes, making them a crucial component of naval warfare. These vessels are categorized into different types, including nuclear submarines and diesel-electric submarines. Nuclear submarines use nuclear reactors for propulsion, allowing them to remain submerged for extended periods, while diesel-electric submarines rely on batteries and diesel engines. Both types play vital roles in national defense and maritime security.