A metal detector is an electronic device used to locate metal objects buried underground or hidden within other materials. It works by generating a magnetic field and detecting changes in that field caused by the presence of metal. Metal detectors are commonly used in various applications, including treasure hunting, archaeological digs, and security screening at airports. These devices come in different types, such as handheld metal detectors and ground search metal detectors, each designed for specific purposes. Users can find items like coins, jewelry, and artifacts, making metal detectors popular among hobbyists and professionals alike.