magnetic poles
Every magnet has two ends where its pull is strongest, called the north pole and the south pole. Hang a bar magnet by a thread and it swings until one end points roughly toward the Earth's geographic north; that end is named the north-seeking pole, or just the north pole. The other is the south pole. It answers the everyday question, why do magnets have a 'front and back' that behave differently?
The basic rule is that like poles repel and unlike poles attract: bring two north poles together and they push apart, but a north and a south pull together. This mirrors electric charge, but with one crucial difference. If you cut a bar magnet in half hoping to separate the north from the south, you do not get an isolated pole; each piece instantly becomes a complete new magnet with its own north and south. There is no such thing as a single magnetic pole (a 'magnetic monopole') in ordinary matter, however small you cut.
Magnetic field lines are drawn leaving a magnet from its north pole and returning to its south pole (outside the magnet). A compass needle is itself a little magnet, and its north pole is pulled toward a magnet's south pole. A subtle twist: because a compass north points toward the Earth's geographic north, the magnetic pole buried near the Earth's geographic North Pole is actually a magnetic south pole.
Snap two fridge magnets together the 'wrong' way and they slide apart or flip; turn one over and they clamp tight. You have found the like-repels, unlike-attracts rule by hand.
Poles always come in north–south pairs; you can never isolate just one.
Do not confuse poles with charge. Unlike electric charges, which can exist singly (a lone electron), magnetic poles never appear alone; the deep reason is that magnetism comes from circulating currents, not from magnetic charge.