In nature an ore (Fe3O4) of the Iron attracts small pieces of irons towards it. This ore is called as magnetite. The phenomenon of attracting small bits of iron towards the ore is called magnetism.
The iron ore showing this effect is called a natural magnet. It is found that a piece of iron or steel can acquire magnetic properties, on rubbing with magnet. Such magnet made out of iron and steel are called artificial magnets.
A bar magnet is the most commonly used form of an artificial magnet. Two ends of the bar magnet are called poles of the magnet.