Photosynthesis is the process where 6CO_2(Carbon Dioxide) and 6H_20(Water) are transformed into C_6H_120_6 (Glucose) and 6O_2 (Oxygen) using sunlight. Cellular Respiration is the exact opposite, using C_6H_120_6 (Glucose) and 6O_2 (Oxygen), breaking it down to Carbon Dioxide, Water, and ATP, a form of energy produced by your Mitochondria.