What is magnetism ?

Hint:Every matter is made up of small particles which are known as atoms.Atoms constitute electrons and when these electrons flow in a well-defined path produces current. Magnetism is created by the moving charges and which produces magnetic fields. Magnetism is a property of every material.

Complete answer:
Every material has a tendency to show magnetism but some of them have exceptionally high potential to show magnetism. Magnetism is a physically occurring event which comes in action by force that causes objects to attract or repel each other by producing their fields, which are known as magnetic fields.

Magnetism is mainly defined as the property to attract or repel a material, the material which shows this property are known as magnets. When we apply an external magnetic field on a material the electron present in it tries to align itself in the direction of the field and forms a domain in many directions. The materials which show this property even in absence of magnetic fields are ferromagnetic substances. In ferromagnetic substances all domains are aligned in the same direction as the magnetic field.

Note:Paramagnetic substances electrons also align themselves in field direction but not all domains are in the same direction due to which these substances are weakly attracted to magnets, ex: Aluminum, sodium, platinum etc. Diamagnetic substances in these all electrons are paired and show no magnetic dipole moment. Hence they are weakly repelled by magnetic fields, ex: Zinc, copper, gold etc.