A magnetic compass that contains a magnet which interacts with the earth’s magnetic field and aligns itself to point to the magnetic poles.
The compass is a navigation item used to tell the orientation of the player. Its commonly used in interaction with a map to maintain the direction in which you are travelling.
To use the compass, you can either drag the item from your inventory on your toolbar, then click the number you equipped it on, and hit space to see it. It can be difficult to see exact numbers on the compass; if you want to get a better view of the numbers, go into your inventory and click “Inspect”.
Prior to 0.54, only the “old” metal compass was available. It now spawns in limited numbers with the “new” plastic compass replacing it in most situations.