Refer to figures.
EASA learning objective 022.03.01.01.03 states: ‘Define the following terms: magnetic variation; magnetic dip (inclination).’

The Earth has fixed geographic (true) North and South poles. Magnetic compasses point to magnetic North which is not in a fixed location and is not in the same location as the geographic North pole! Due to the molten nature of the Earth's core the magnetic field and hence the magnetic poles are in a state of constant movement. The magnetic North pole is currently situated in northern Canada and the magnetic South pole is near the edge of Antarctica, they move about 10 miles every year.

Magnetic variation is the angle between the direction of True North and Magnetic North expressed in degrees East or West, its value will vary with your location on the planet. For example, in central UK at the moment the direction of True North and Magnetic North are aligned so the variation is zero degrees. However if youwere in Canada and flew over Magnetic North on the way to geographic North Pole the variation would be 180° and your magnetic compass would indicate South despite that fact that you're heading North!