Magnetic north remains constant at a particular location, while true north shifts with time. Moreover, magnetic north is the direction pointed out by the compass needle and true north is a permanent location on the Earth.
Magnetic north definition
Magnetic north is the direction a magnetic compass would point at the time the map was published. The direction of magnetic north varies over time and with the position on the surface of Earth. Thus, magnetic declination values on the old maps are no longer accurate.
In other words, the north direction in the magnetic field of Earth is indicated by the north pole of a compass needle.