The type of waves used in sonar technology is ultrasonic waves. Sonar, which stands for Sound Navigation and Ranging, utilizes these high-frequency sound waves to detect and locate objects underwater. The technology works by emitting ultrasonic pulses that travel through water, reflect off objects, and return to the sonar device, allowing for distance and location calculations. Sonar is extensively used in various applications, including navigation in submarines, fishing, and exploring underwater terrains, as well as in oceanography.