1. Different expressions of meaning
1. True North: It is the direction along the surface of the earth towards the geographical North Pole.
2. Magnetic North: It is the north indicated by the compass.
2. Different reasons
1. True north: The intersection of the true meridian at point P on the ground and the surface of the earth is called the true meridian, and the true meridian is in the north direction of the tangent to point P.
2. Magnetic North: Since the poles of the earth's magnetic field do not coincide with the geographical north and south poles, the north indicated by the compass is magnetic north rather than true north.
3. Different characteristics
1. True North: The direction of true north in astronomy is marked in the sky at the North Celestial Pole. This is about 1° from the position of Polaris, so the star will track a small circle in the sky each sidereal day.
2. Magnetic North: Magnetic North changes over time.
Baidu Encyclopedia - True North
Baidu Encyclopedia - Magnetic North