Evapotranspiration differs from evaporation in the following ways: a. Evapotranspirtation deals only with a change of state over water surfaces such as oceans, seas and lakes. b. Evapotranspirtation refers to transfer of moisture from clouds to landsurfaces, also known as precipitation. c. Evapotranspirtation refers to transfer of moisture from land surfaces such as plants or soils to the atmosphere. d. Evapotranspiration refers to all of the moisture in the atmosphere in varying states of transport.

Evapotranspiration is an important component of the water cycle. This process is the main user of solar energy on the earth's surface. This energy is called latent heat flux. Evapotranspiration is responsible for 15% of the atmospheric water vapor. Factors affecting evapotransiration include:

The availability of energy
Humidity away from the surface gradient
Wind speed above the surface
Availability of water
Physical characteristics of vegetation
Soil attributes