6CO2 + 6H2O + light energy = C6H12O6 + 6O2.
Carbon dioxide + water+ light= glucose(sugar) + oxygen
This is neccesairy for the survival of animals because it creates the oxygen we need, as well as uses some of the carbon dioxide we create. Additionally, the ability of plants to make sugar via photosynthesis is where all of our energy and nutrition comes from. All animals use the sugar that plants create to survive.