The main type of energy used in photosynthesis is solar energy, or light energy, which is captured by chlorophyll present in plant leaves. During this process, plants use sunlight to convert carbon dioxide from the atmosphere and water from the soil into glucose and oxygen. This glucose serves as food for the plant, while oxygen is released as a byproduct, contributing to the Earth's atmosphere. The ability of plants to harness solar energy through photosynthesis is essential not only for their survival but also for sustaining life on Earth as it forms the basis of the food chain.