Whenever a magnetic field is applied in any material magnetic moments are induced. Diamagnetism is the property in which the resultant magnetic field is less than the applied field as the magnetic fields due to induced dipole moments opposes the original field.

Therefore, property of diamagnetism is exhibited by all materials. However in some cases the magnetic field is able to align dipoles in its direction. This results in differentiation of some materials into para and ferro-magnetic.

When the resultant magnetic field in the material is greater than the applied field then the material is paramagnetic.

Whereas some materials have a strong tendency to align themselves even without any external field such materials are ferro-magnetic.