Magnetism is one aspect of the combined electromagnetic force. It refers to physical phenomena arising from the force caused by magnets, objects that produce fields that attract or repel other objects.
All materials experience magnetism, some more strongly than others. Permanent magnets, made from materials such as iron, experience the strongest effects, known as ferromagnetism. With rare exception, this is the only form of magnetism strong enough to be felt by people.
All magnets have a north pole and a south pole. Like poles repel but opposite poles attract each other. Electrons in the atoms of magnets spin around the nucleus mostly in one direction, this is how the two poles are created. The magnetic force flows from the north pole to the south pole of the magnet.