Transpiration is the process by which water molecules evaporate and escape from the aerial parts of the plants.
A tension is created in the plant due to transpiration and this acts as a driving force for the uptake of water from the soil and the movement of water to the shoots.
The water that is now made available to the photosynthetic parts of the plants, like leaves, is utilized for the photosynthetic process.
During transpiration, the stomata are open to allow the escape of water. Simultaneously, the exchange of gases crucial for photosynthesis occurs.