Intermolecular forces refers to forces between two different molecules of a compound

Intermolecular forces refers to forces between two different molecules of a compound. For example, if you have two water molecules next to each other, the attraction they have for one another will be an intermolecular force. Examples of intermolecular forces include London dispersion forces, dipole-dipole forces, and hydrogen bonds).

Intramolecular forces refers to the forces that keep the atoms in a molecule bound to one another - in other words, chemical bonds. Covalent bonds are the only intramolecular forces known, because only exist as molecules.