A magnetic compass is a device that tells you which direction is north, south, east, or west. It does this by using the Earth's magnetic field. The needle on the compass points in the direction of the Earth's magnetic North Pole.
The first compasses were made of lodestone, a natural magnet. The magnets in a modern compass are usually made of an alloy called Alnico. The word compass comes from the Latin word for circle. A circle has 360 degrees. So when we say that something is due north, south, east, or west, we mean that it is at a certain number of degrees from north. For example, if you are standing at the North Pole (0 degrees), then due south would be at 180 degrees.
Compasses are very useful tools. They have helped people find their way around for centuries. They are still used today by hikers and sailors and anybody else who needs to know which way is north!