It is the science and art of cultivating plants and rearing animals for food, fiber, fuel, and other products used to sustain human life. It was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that supported a more densely-populated, sedentary lifestyle. The study of agriculture is known as agricultural science. The history of agriculture dates back thousands of years, and its development has been driven and defined by greatly different climates, cultures, and technologies. Modern relies on technological advances in breeding, genetics, irrigation, mechanization, and pesticides. Target markets for agriculture can be broadly classified into two groups: those who purchase for consumption (e.g. grocery stores, restaurants) and those who purchase for further processing (e.g. food manufacturers, textile mills). The industry is vital for both groups, as they provide the raw materials that these businesses need to operate. The industry has a significant impact on the economy, as it is responsible for providing food and other essential products. The industry is also a major employer, with over 24 million people employed in agriculture-related occupations in the United States alone. In addition to its economic contributions, It also plays an important role in environmental stewardship and preserving natural resources.