True north is a geographical direction, whereas magnetic north is a reading on a compass. True north never changes; it represents how you get from one point to another on a map by following the lines of longitude.
Magnetic north is a point in arctic Canada that shifts location because of the Earth's magnetic fields. The difference between true north and magnetic north is called the magnetic declination. There are areas in the world where true north and magnetic north align that are called agonic lines. The easiest way to find true north is with a Global Positioning System (GPS).