Video narration
How can a magnet pull an iron nail-and what does that have to do with a fridge magnet lifting a paper clip? Inside the nail, tiny magnetic regions point in many different directions. Their effects mostly cancel, so the nail doesn't act like a magnet on its own. Bring the fridge magnet close. Its magnetic field-the space around it where magnetic forces act-lines up more of those regions inside the nail. But the nail isn't just being tugged from outside. The magnet makes the iron in the nail act like a magnet too. Now the nail's near end becomes the opposite pole, so it is drawn toward the magnet. That's how the fridge magnet lifts a paper clip: its iron-containing steel responds to the field, with the near end becoming the opposite pole.