The process by which plants make their food is called photosynthesis. During photosynthesis, plants convert carbon dioxide and water, utilizing sunlight as energy, primarily through the chlorophyll in their leaves. This process results in the production of glucose, which serves as food for the plant. Oxygen is released as a byproduct of this process, contributing to the atmospheric oxygen that is essential for most living organisms. Photosynthesis is fundamental to life on Earth, as it is the primary means by which energy from sunlight is captured and stored in the form of chemical energy.