Inductor is an electrical component that stores energy in magnetic field.
The inductor is made of a coil of conducting wire.
In an electrical circuit schematics, the inductor marked with the letter L.
The inductance is measured in units of Henry [L].
Inductor reduce current in AC circuits and short circuit in DC circuits.
Inductor 

Iron core inductor 

Variable inductor 
For several inductors in series the total equivalent inductance is:
L_{Total} = L_{1}+L_{2}+L_{3}+...
For several inductors in parallel the total equivalent inductance is:
X_{L} = ωL
Cartesian form:
Z_{L} = jX_{L} = jωL
Polar form:
Z_{L} = X_{L}∠90º