Quick Cohesive forces are the forces between the molecules of a substance. They forces between like molecules, such as water and water.
Adhesive forces are the forces between the molecules of different substances. They forces between unlike molecules, such as water and glass.
Details
The relative strengths of adhesive and cohesive forces determine whether the meniscus curves up like the meniscus of water in glass or down like the meniscus of mercury in glass and whether a liquid rises or falls in a capillary. If the adhesive forces are stronger than the cohesive forces, as is the case for glass and water, the meniscus is concave, and the liquid rises in a capillary. The attraction of glass for water pulls water that touches the glass up, and surface tension makes the rest of the surface of the water follow.
Surfactants or wetting agents in dishwater and laundry detergents lower the surface tension of water, and the adhesive forces are better able to make water spread out over (wet) the surfaces being cleaned.
If the cohesive forces are stronger than the adhesive forces, as is the case for mercury and glass, the meniscus is convex, and the level of the liquid falls in a capillary. The cohesive forces in water are stronger than the adhesive forces between water and wool. As a result, water does not spread through wool fabrics, and wool clothing does not get as wet in rainy weather as cotton clothing.
Related ▪ L - Surface Tension
▪ L - Wetting, Nonwetting, and Contact Angle
▪ L - Capillary Effect