Sonar, which stands for Sound Navigation and Ranging, is a technology that uses sound waves to detect and locate objects underwater. It works by emitting sound pulses and analyzing the echoes that return after bouncing off objects, such as submarines or the ocean floor. This method is crucial for navigation, fishing, and underwater exploration. There are two main types of sonar: active and passive. Active sonar sends out sound waves and listens for their echoes, while passive sonar only listens for sounds made by other objects. Both types are essential for various applications, including marine research and military operations.