The process by which plants lose water vapor through their leaves is called transpiration. During transpiration, water absorbed by the roots travels through the plant and evaporates from tiny openings called stomata in the leaves. This process not only helps regulate temperature but also aids in the uptake of nutrients and minerals from the soil as it creates negative pressure that draws water upward. Transpiration is essential for maintaining the overall health of plants and contributes to the water cycle in the environment.