* Plants: The most familiar example, plants use sunlight, water, and carbon dioxide to produce their own food (sugars) and release oxygen as a byproduct.
* Algae: These single-celled or multicellular organisms, which can be found in freshwater, saltwater, and even snow, are also photosynthetic.
* Cyanobacteria: These bacteria are also photosynthetic, often called blue-green algae. They were crucial in the early evolution of life on Earth by producing oxygen.
While some bacteria are photoautotrophs, most bacteria are not. They are heterotrophs, meaning they get their energy from consuming other organisms.
