Magnetism basically consists of lines considered impossible to be seen of forces created by types of natural magnets and also by the known as electromagnet.
Among the most common types of natural magnets, the three main ones are the needle found in the compass, the horseshoe used in animals, and the bar. The magnets have two main specifications, they can attract and attach to any material containing iron, and if they are free to move, such as the compass needle, for example, have the ability to point to the north or south.
In electric motors, each magnet has two poles, one is the north pole and the other is the south pole. The lines impossible to be seen in the magnetic flux leave the north pole and go towards the south pole. Just as the flow lines are invisible, the effects of the magnetic field created by them, depending on the situation, may even become visible.
If a sheet of paper is placed on a natural magnet or an electromagnet, and iron filings are placed on it, the iron filings may be deposited along the invisible lines of the stream.