Wet is a term that describes how a liquid clings to another material, for example cloth. When the liquid molicules are attracted to the material they can wet it. But water does not wet all materials. For example water beads up on a car's highly pollished hood because water is repelled by wax. Oil and water do not mix and water will not wet your hands if covered with oil or grease. Laundry detergent or dishwashing detergents are wetting agents that help water to wash away oil and grease. Finally, water is called the universal solvent because it can disolve many materials (even glass in very small amounts) and is therefore capable of wetting a wide variety of materials that it can disolve.