I recently learnt that intermolecular force is the force of attraction between molecules and van der Waals force does the same so is there any difference ?
2 Answers
Cohesion refers to the force of attraction between two of the same molecules, whereas adhesion refers to the force of attraction between two foreign molecules.
This is better depicted in the image below.
Van der Waals force simply refers weak electrostatic forces of attraction AND repulsion, caused by electric dipole moments.
Intermolecular forces are any forces between molecules and include both attractive and repulsive forces. Van der Waals is one of these forces, and is a distance-dependent interactions between atoms or molecules. Van der Waals is different than ionic or covalent bonds as they are not a result of a chemical electronic bond, and are comparatively weak and more susceptible to being perturbed.
See Wikipedia - Van der Waals force for more details.