The Earth has often been described as the Blue Planet. This is the result of the blue colour reflected in sunlight from the large expanse of water and the refraction of shorter wavelengths from the atmosphere, especially clouds. The green colouration is almost entirely due to one pigment, chlorophyll, which is the most important bio-molecule on the planet. Chlorophyll is the key molecule of photosynthesis which itself is the most important biological process on our planet and without which life on our planet as we know it would be impossible.
Photosynthesis is the process by which light energy is converted into chemical energy.
In this equation the emphasis is on the conversion of an inorganic molecule carbon dioxide into an organic molecule - the sugar, glucose. It almost passes us by that light is necessary for the reaction. It is just a summary - a summation of a large set of chemical equations. Despite its short-comings the simple equation is a useful way to understand those events that make up the vital process of photosynthesis. It reminds us that the process involves the formation of organic carbon from carbon dioxide and water, both of which are plentiful on our planet.