A submarine is a watercraft capable of underwater operation. It is designed to navigate beneath the surface of the water, allowing it to perform various tasks such as research, exploration, and military missions. Submarines can be powered by nuclear or diesel engines and are equipped with advanced technology for navigation and communication. Submarines are often used by navies around the world for defense purposes, including surveillance and stealth operations. They can carry torpedoes and missiles, making them a crucial part of modern naval warfare. The design of a submarine allows it to withstand high pressure and remain submerged for extended periods.