Photo-, root meaning light, and -synthesis, root coming from greek suntithenai, means to put together (make chemical compounds react with each other, is the simple answer ✧ꉂ(σ▰˃̶̀ꇴ˂̶́)σ✧).
Photosynthesis takes place in plants where they use light's energy to turn absorbed water and carbon dioxide into their food, also known as glucose, and they also release oxygen in the process.
The exact formula is:
6CO2 + 6H2O + light energy --> C6H12O6 + 6O2
