Magnets

Bar magnets are magnets in the shape of a bar. Magnets contain a north and south pole and all bar magnets have magnetic fields around them. Opposite poles will attract each other whereas the same poles will repel. The Earth also has magnetic fields. It also has a north and a south pole. This is why a compass points to north, because the metal is attracted.

Electro-Magnets are magnets that can be turned on and off. A current going through a wire causes it to have a magnetic field. You can also change the strength of an electro-magnet by increasing the current or turns of wire.