Photosynthesis (from the Greek word photo, meaning “light,” and synthesis, from the Greek work syntithenai, which means “to put together”) is the process by which plants use energy derived from light in order to make food molecules from carbon dioxide and water. Oxygen (O2) is produced as a waste product of this process. Photosynthesis is a dual-staged process with multiple components. Ultimately, photosynthesis is the process that provides food for the entire world. Each year more than 250 billion metric tons of sugar are created through photosynthesis. Photosynthesis is a source of food not only for plants, but also all organisms that are not capable of internally producing their own food, including humans.