Each magnet has two poles, one being a north pole and one south pole. In this way, the invisible lines of the magnetic flux will start from the north pole towards the south pole. Even if the flow lines are invisible, the effects of the magnetic field produced by them may become visible.
If a sheet of paper is placed on a natural magnet or on an electromagnet, and an iron filament is spilled on this sheet, the iron filings will be arranged along the invisible lines of the flow. Dashed lines will indicate the path of magnetic flux lines. The field lines remain in and out of the magnet, thus forming closed loops. The magnetic flux lines will exit the north pole and enter the south pole, returning to the north pole through the magnet.
The instant that two magnets are placed next to each other, the magnetic flux that exists in the surroundings of the magnet, can cause a significant interaction between them. If, by chance, the magnets come in with the opposing poles, they may have the attraction phenomenon, and if they have the identical poles, they will need to repel.