Sonar devices, short for Sound Navigation and Ranging, use sound waves to detect and locate objects underwater. They emit sound pulses that travel through water, bouncing off objects and returning to the device. By measuring the time it takes for the sound waves to return, sonar can determine the distance and shape of underwater features, such as shipwrecks or submarine terrain. There are two main types of sonar: active sonar, which sends out sound waves, and passive sonar, which listens for sounds made by other objects. Sonar is widely used in various fields, including marine biology, fishing, and naval operations, helping to enhance our understanding of underwater environments.