The term "food source" refers to any plant or animal that provides food for humans, animals and other organisms. This can include crops such as wheat, corn, fruits, vegetables, fish, meat, poultry, dairy products, nuts, seeds, etc., which are all necessary for survival and sustenance of life on earth. Food sources also refer to the natural environment in which these plants or animals thrive, including soil, water, air, sunlight, temperature, and other factors that contribute to their growth and reproduction. In a broader sense, food sources can include any substances that provide energy for living organisms, such as fossil fuels, which are used by humans to produce food through agriculture or industry.