A galvanometer is a device that measures small electric currents through mechanical motion generated by electromagnetic forces, working on the principle of converting electrical energy into mechanical energy. It comprises essential parts including a U-shaped magnet, a flat coil of wire, and a pointer, and operates by experiencing magnetic deflecting torque due to current flow, reaching equilibrium when restoring torque counteracts deflection. Galvanometers can serve as ammeters and are utilized in various applications such as laser scanning and in recording, positioning, and servomechanism equipment.