Adhesion refers to molecular interactions between the contact surfaces of different substances. These interactions are also known as adhesion forces.
They can be observed, for example, when paint adheres to paper or when two workpieces are glued together. In contrast to adhesion, cohesion refers to the forces that act between the molecules of a single substance.
Based on the relationship between the forces of adhesion and cohesion, liquids exhibit different wetting behavior in connection with a solid surface.