A transformer because, to work, it must use mutual inductance between its separate windings.

Mutual inductance describes the process by which a changing current in one coil, creates a changing magnetic flux which, when it links with a second coil, induces a changing voltage into that coil.

1. self- induction2. mutual- induction

inductor is a electronic component that resist a change in the flow of current inductance is that property of inductor.

mutual inductance