The term food system is used frequently in discussions about nutrition, food, health, community development and agriculture. A food system includes all processes and infrastructure involved in feeding a population: growing, harvesting, processing, packaging, transporting, marketing, consumption, distribution and disposal of food and food-related items. It also includes the inputs needed and outputs generated at each of these steps. A food system operates within and is influenced by social, political, economic, and environmental contexts. It also requires human resources that provide labor, research and education. Food systems are either or according to their model of food lifespan from origin to plate.