The process by which energy is derived from the sun is known as photosynthesis. During photosynthesis, plants, algae, and some bacteria convert sunlight into chemical energy using chlorophyll, a green pigment present in their cells. This process occurs mainly in the chloroplasts and involves capturing light energy to convert carbon dioxide and water into glucose and oxygen. Photosynthesis is vital for life on Earth, as it provides the primary energy source for nearly all ecosystems and contributes to the oxygen content of the atmosphere.