In a magnet, the magnetic domains in a substance are aligned. A magnet can be regarded as having two magnetic poles, one north and one south. However, if you were to cut a magnet in half, you would never get a north piece of magnet and a south piece of magnet. You would instead end up with two smaller magnets.
The Earth's magnetic field has a north and south pole. We can use the magnetic field of the Earth to help navigate by using a compas. Compasses can also be used to figure out which side of a magnet is the north or south pole of that magnet.
See also: