- materials that can be magnetized like [[Iron]] are composed of tiny regions called domains - each of these has a north and south pole - when [[Iron]] is unmagnetized, the domains are randomly oriented throughout the metal - but when the metal is magnetized, all of the domains align - for example, you can magnetize a steel bar by rubbing the steel with a magnet - this lines all the domains in the same direction - even after you take away the magnet the steel bar stays magnetized now