An ultrasonic sensor is a device that uses sound waves to measure distance. It emits high-frequency sound waves that bounce off nearby objects and return to the sensor. By calculating the time it takes for the sound waves to return, the sensor can determine how far away the object is. This technology is commonly used in various applications, such as parking sensors in cars and distance measuring tools in robotics. These sensors are popular because they are non-contact, meaning they can measure distances without touching the object. They are also effective in different environments, including water, air, and vacuum, making them versatile for many industries, from automotive to manufacturing.