Magnets can be roughly divided into three types: temporary magnets, permanent magnets, and electromagnets.

Magnets are classified according to their magnetic source.

1、 Temporary magnet

Temporary magnets will be magnetized in the presence of a magnetic field. When the magnetic field is removed, they gradually lose their magnetism. Some irons and ferroalloys, as well as Paper clip and nails, act as temporary magnets.

2、 Permanent magnet

Permanent magnets do not easily lose their magnetism. These magnets may be naturally occurring ("rare earth") elements or compounds.

Examples of permanent magnets include neodymium iron boron (NdFeB) and ferrite (a ceramic like material made from a mixture of iron oxide and nickel, strontium, or cobalt).

3、 Electromagnet

An electromagnet generates a magnetic field by causing an electric current to flow through a coil with a metal core, creating an energized coil. When the current disappears, the magnetic field also disappears.