What's the difference between try north and magnetic north?

It's on tr iPhone compass it showed up and I was just wondering what is the difference

True North is the imaginary point where the axis of the Earth's spin comes through the surface. Magnetic North is the imaginary point where if the Earth was a giant magnet, the paper clips would stick straight up. The two might seem the same, but actually they are almost completely unrelated.

True North is the 'Theoretical position' of the Axis that the Earth spins on, and is a position on a map, in fact it moves slightly as the Earth rotates around the sun year to year.

Magnetic North is where a Compass points (and where Top Gear went some years ago) it is actually to the side of True north by some hundreds of miles and Compasses point there as there is a higher concentration of Iron Ore just North of Canada and the fluid centre of the Earth (that causes compasses to point at all) centres on.

Once you are below a certain Parallel it doesn't make enough difference when finding your way by compass, although most maps allow for it.

In the Legend on an Ordnance Survey map it gives instructions for finding North, from Compass North.

Learnt went the world was still young and I was in Scouts lol.

Truth North is the direction of a grid line which is parallel to the central meridian on the National Grid. Magnetic North is the direction indicated by the magnetic compass. It is always moving and we call it margin of declination. The horizontal angular difference between True North and Magnetic North is called MAGNETIC VARIATION or DECLINATION. It given for each corners of map and is shown in the legend as is the difference between truth north and magnetic north.