A magnet is made of hard magnetic material that attracts ferromagnetic materials (iron, nickel…). It has two opposite poles, called the north and the south, which generate the magnetic field. This field enters the magnet’s south pole, and exits at the north pole, creating lines of force along which iron filings or the needle of a compass will align themselves.

The magnetic field created by a magnet acts at a distance, and can be observed using an array of compasses. A single click shows how those lines of force are arranged around the magnet. Note that these lines are attached to the magnet.