Capillary fringe refers to the zone of water-saturated soil located above the water table. This area is also known as the capillary zone, capillary fringe zone, and unsaturated zone. The capillary fringe zone exists because soil has a property known as capillary action. This allows water molecules to move upward through the soil, causing soil pores to become filled with water. Other synonyms include the vadose zone, the aeration zone, and the soil-moisture zone. The capillary fringe plays a vital role in groundwater management and water retention. Understanding the behavior of the capillary fringe is crucial in preventing groundwater contamination and ensuring the sustainability of water resources.