The process by which liquid water becomes vapor is known as evaporation. This physical process occurs when water molecules gain sufficient energy to overcome intermolecular forces, transitioning from the liquid phase to the gaseous phase. Evaporation typically occurs at the surface of a liquid and can be influenced by factors such as temperature, surface area, and air movement. It plays a crucial role in the water cycle, contributing to cloud formation and precipitation, and also impacts weather patterns and climate.