How do magnets work?

You've stuck a magnet to your fridge a thousand times. Click — it just hangs there, defying gravity, holding up your grocery list like it's no big deal. But inside that little chunk of metal, something invisible is happening. Something organized. Something powerful.
Every magnet is made of atoms, and every atom is like a tiny spinning top with an invisible arrow pointing out of it. That arrow is called a magnetic moment — think of it as the atom's personal north-south direction. In most materials, these atomic arrows point every which way, canceling each other out. No magnetism. But in a magnet, millions of arrows line up in the same direction, all pointing the same way like soldiers in formation.
