Video narration
Electromagnetic induction is the link between magnetism and electricity. If the magnetic field through a wire loop changes, an emf is induced, and a current can flow. For example, move a bar magnet toward a coil: the magnetic field through the coil increases, so a meter needle deflects or a bulb may glow. Pull the magnet away: the field decreases, and the induced current changes direction. So the key idea is simple: changing magnetic field → induced emf → induced current.