During photosynthesis, plants absorb sunlight through chlorophyll, a pigment in their cells. This light energy is used to convert carbon dioxide from the air and water from the soil into glucose, a type of sugar that serves as a source of energy for the plant. Oxygen is released as a byproduct of this process, which is essential for most living organisms. Photosynthesis is crucial for the survival of plants and plays a significant role in the Earth's ecosystem by producing oxygen and serving as the foundation of the food chain.