Photosynthesis is a process that only plants and certain cyanobacteria can perform.
In this, a gas called carbon dioxide, when combined with sunlight and water, is turned into sugars (a solid) and oxygen (a gas) through a sequence of processes.
Sugar (glucose) formation is a chemical way of storing solar energy as a source of energy (food), which is a fuel for plants.
Photosynthesis products provide energy for plant development, maintenance, and growth.
Plants use glucose to generate starch and cellulose, among other things.