Ferromagnetic substances get strongly attracted towards magnetic field.
They can be permanently magnetized.
In solid state, the metal ions of ferromagnetic substances are grouped together into small regions and are known as domains that act as a tiny magnet.
In an unmagnetised ferromagnetic substance the domains are randomly oriented that cancels out their magnetic moments.
When placed in a magnetic field all the domains of the substance get oriented in the direction of the magnetic field producing a strong magnetic effect which persists even on removal of the magnetic field and the ferromagnetic substance becomes a permanent magnet.
For example, iron, cobalt, nickel, gadolinium and CrO2 are ferromagnetic substances.
Whereas in case of Antiferromagnetism domains are oppositely oriented thereby cancel out each other's magnetic moment. For example, MnO.