Georg Simon Ohm was a German physicist who formulated Ohm's law, which describes the mathematical relationship between electrical current, resistance, and voltage. Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them. It is represented by the equation V=IR, where V is voltage, I is current, and R is resistance. Ohm's law is the core equation used to study electrical circuits and analyze different components of a circuit.