Revisiting Ampere's Law
Ampere's Law as written allows us to calculate the magnetic field due to an electric current.
We also know that a changing electric field produces a magnetic field
Combine effects of electric current and changing E field on magnetic field to obtain a more complete version of Ampere's Law
Contribution due to the penetrating current is known a conduction current.
Contribution due to changing electric field is known as the displacement current
Final Ampere's Law