Electromagnetic methods are geophysical techniques used to explore subsurface materials by measuring the Earth's natural or induced electromagnetic fields. These methods can help identify resources like minerals, oil, and groundwater by analyzing how different materials respond to electromagnetic waves. In practice, electromagnetic surveys involve sending electrical currents into the ground and measuring the resulting magnetic fields. This data is then interpreted to create images of the subsurface structure. Common applications include mineral exploration, environmental studies, and archaeological investigations, making electromagnetic methods a versatile tool in geoscience.