How does a compass work?

how does a compass work?

The compass is a simple instrument that makes use of the earths magnetic fields to determine something called magnetic north. This point is different from true north which is a concept derived from mathematically (and artificially) dividing the earth into hemispheres and smaller divisions with the lines we call latitude and longitude. The difference between true north and magnetic north is called magnetic declination and varies by a measurable and predictable number of divisions every year. That the earth's own polarity (just like any magnet which has a north and south pole, so too is the earth a giant magnet) has shifted over time is useful in understanding the evolution of the earth and the position its found in today.
I think that explanation should suffice but I'm happy to offer more if you so wish