Vander Waals is an attractive universal force that operates when the atoms and molecules are within a distance range of 0.4- 0.6 nm.
The attractive force closely gathers the atoms and molecules, so their collective strength can affect the state and other physical properties like melting and boiling points, viscosity, etc.
The participating atoms and molecules are polar and nonpolar in nature. They do not carry any charge like the ions in ionic bonds nor form any physical bond as seen in covalent.
Therefore, the strength of the van der Waal interactions is lower than the ionic and covalent bond strength and typically ranges from 0.4 kJ/mol to 40 kJ/mol.
Such van der Waal forces are of three types based on the nature of the participating atoms or the molecules- Polar- Polar (Keesom Forces), Polar- Nonpolar (Debye Forces), and Nonpolar- Nonpolar (London Forces).
Examples of some atoms and molecules interacting using van der Waal forces are HCl, He, H2O, CH4, etc.