I bet you answer this question!
Very simply, all the atoms that make up a magnetic material have a very slight magnetic field. When this is a magnet - which can be caused, for example, using another magnet, like when a magnet is used on a nail - all these atoms line up and their magnetic fields combine, causing an effect that can be observed and used. Any action that causes these atoms to lose their line will reduce the magnet's strength - dropping/hitting a magnet and passing a powerful electric current through it are two things that will do this, eventually removing any noticeable magnetism. Hope that helps!
