The phenomenon in which the surface of a liquid is elevated or depressed when it comes in contact with a solid. The result depends on the outcome of two opposing forces, Adhesion and Cohesion.

Adhesion between glass and water causes the water to rise along a glass wall until this force is balanced by the cohesive force acting to minimize the liquid's surface area (Surface Tension). When adhesion is less than cohesion, as with glass and mercury, the surface is lowered. The upward flow of water in soil and in plants is partially caused by capillarity.