what is the difference between intermoleculat forces and intramolecular forces?

Please read :

(Metallic bonds and ionic bonds are neither internolecular forces nor intramolecular forces because metallic bonds involve metal atoms and ionic bonds involve opposite ions, but NOT molecules in both cases.)

Inter- : between, among
Intra- : inside, within

Intermolecular forces are the forces that act between different molecules. For example the attraction between two water molecules is intermolecular force (van-der-waals).

Intramolecular is within a single molecule. For example the covalent bonds between two hydrogrens and an oxygen atom in water molecule, these covalent forces are intramolecular force. (covalent, metallic and ionic bonding)

Intramolecular forces are much stronger than intermolecular forces. :)))