How can Transformers do their Job?

-They contain 2 Coils: Primary and Secondary Coil -Those cores are joined via an Iron Core -When an Alternating Potential Difference is given to the Primary Coil, it makes an Alternating Magnetic Field -Iron, too joins in and creates a Magnetic Field due to the Primary Coil. But since the Coil's alternate, the Irons will as well -And this Changing Magnetic Field gives the Secondary Coil an Induced Potential Difference