Intermolecular forces are forces between separate molecules that hold the substance together. There are three main types; dipole-dipole interactions, hydrogen bonding and London dispersion forces, which are also sometimes just referred to as Vand Der Waals forces. These forces are typically fairly weak and don't require much energy to break. Intramolecular forces are the forces within molecules. There are three main types of these forces; covalent, ionic and metallic. Intra molecular forces are very strong by comparison to intermolecular forces.