Inductance can be defined as ability of the coil of wire to resist any change in electric current passing through the coil.

According to faradays law, the inductance L may be defined in terms of the emf generated to oppose a given change in the current.

The value of an inductance is directly proportional to the number of turns wound or used.

Note:
Faradays Law:
Any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be "induced" in the coil. No matter how the change is produced, the voltage will be generated. The change could be produced by changing the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out of the magnetic field, rotating the coil relative to the magnet, etc.