Magnetic declination (also called magnetic variation) is the angle between magnetic north and true north at a particular location on the Earth's surface. The angle can change over time due to polar wandering.
Magnetic north is the direction that the north end of a magnetized compass needle points, which corresponds to the direction of the Earth's magnetic field lines. True north is the direction along a meridian towards the geographic North Pole.
A compass rose or compass star, sometimes called a wind rose or rose of the winds, is a polar diagram displaying the orientation of the cardinal directions (north, east, south, and west) and their intermediate points. It is used on compasses (including magnetic ones), maps (such as compass rose networks), or monuments. It is particularly common in navigation systems, including nautical charts, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems, satellite navigation devices ("GPS").
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