The process by which plants make food using sunlight is called photosynthesis. During photosynthesis, plants convert carbon dioxide and water into glucose and oxygen, utilizing sunlight as an energy source. This process occurs primarily in the chloroplasts of plant cells, where chlorophyll captures light energy. Photosynthesis is foundational for life on Earth as it not only provides energy for plants but also produces oxygen, which supports the respiratory needs of most living organisms. This natural process is essential for sustaining ecosystems, agriculture, and the planet's atmosphere.