In order to live we need energy. We get that energy from food. We humans eat by chewing. Food enters the stomach through our mouth and is thus digested. But if you can’t chew and don’t have a stomach, do you eat? Plants also need energy. So they also have to “eat”. Actually, plants do that much better; they are able to provide themselves with energy. They make the sugars they need for life energy themselves. By means of photosynthesis (something only plants can do!) a plant produces its necessary fructose with water, carbon dioxide (CO2) and light.
Plants form the basis of the food chain. This selfmade energy is used by all the following organisms.