An inductor is an electronic component that is designed to store energy in a magnetic field when an electrical current flows through it. It is also sometimes called a coil, reactor or choke.
Inductors are made by winding a coil of conducting wire around a core made of a magnetic material, such as iron or ferrite. The amount of inductance, measured in henries (H), depends on the number of turns in the coil, the cross-sectional area of the core, and the permeability of the core material.
Inductors are used in a wide variety of electronic circuits for a range of purposes, including filtering out unwanted frequencies in a signal (in a filter circuit), storing energy in a circuit (in a power supply), and limiting the rate of change of current (in a smoothing circuit).