Autotrophs create their own food primarily through the process of photosynthesis. During photosynthesis, autotrophs, such as plants, algae, and some bacteria, use sunlight, carbon dioxide, and water to produce glucose (a sugar) and oxygen. This process occurs mainly in the chloroplasts of plant cells and involves the conversion of solar energy into chemical energy.
Cellular respiration, on the other hand, is the process by which organisms, including autotrophs, break down glucose to release energy for use in their cells. While cellular respiration is crucial for energy production, it is not the process by which autotrophs create their own food.