A metabolic process involving plants and some types of bacteria (e.g. Chromatiaceae, Rhodospirillaceae, Chlorobiaceae) in which light energy absorbed by chlorophyll and other photosynthetic pigments results in the reduction of $\ce{CO2}$ followed by the formation of organic compounds. In plants the overall process involves the conversion of $\ce{CO2}$ and $\ce{H2O}$ to carbohydrates (and other plant material) and the release of $\ce{O2}$.