You have probably experimented with magnets and have seen for yourself how they attract and repel other magnetic metals.
Certain metals—iron, cobalt, and nickel—contain electronically charged atoms that arrange themselves to produce two forces, called a positive force and a negative force, at either end of their surface. A positive force attracts a negative force and repels a positive force. These charged metals are magnets.
Earth itself has a magnetic field. The cause of Earth’s magnetic field is not fully understood, but seems to be a result of the metals within its core. The core acts something like a huge magnet, as if a big bar magnet were inside Earth.
The strongest points of the magnetic field—called poles—are at the north and south. The north pole is the positive pole and the south pole is the negative pole.
Opposite poles attract and like poles repel each other, so a compass with a magnetized needle will always swing its negative point (pole) to the north.