The main difference between intramolecular forces and intermolecular forces is that, intramolecular forces are the forces that hold atoms together. However intermolecular forces are forces that exist between molecules. Also, there are some smaller differences. For example, an intramolecular force is stronger than an intermolecular force, intramolecular forces determine chemical behaviour of a substance whereas intermolecular forces determine the state of matter and their physical properties. Intermolecular forces are attractive forces while intramolecular forces are chemical bonds. They are also categorised very differently, intramolecular forces are categorised into covalent, iconic and metal bonds, when intermolecular forces are categorised into dipole-dipole forces, London dispersion forces and hydrogen bonding forces. In conclusion while these two forces seem very similar they are in fact very different.