Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of the secondary sector of the economy. The term may refer to a range of human activity, from handicraft to high-tech, but it is most commonly applied to industrial design, in which raw materials from the primary sector are transformed into finished goods on a large scale. Such goods may be sold to other manufacturers for the production of other more complex products (such as aircraft, household appliances, furniture, sports equipment or automobiles), or distributed via the tertiary industry to end users and consumers (usually through wholesalers, who in turn sell to retailers, who then sell them to individual customers). Manufacturing engineering is the field of engineering that designs and optimizes the manufacturing process, or the steps through which raw materials are transformed into a final product. The manufacturing process begins with the product design, and materials specification. These materials are then modified through manufacturing to become the desired product. Modern manufacturing includes all intermediate processes involved in the production and integration of a product's components. Some industries, such as semiconductor and steel manufacturers, use the term fabrication instead. The manufacturing sector is closely connected with the engineering and industrial design industries. Etymology The Modern English word manufacture is likely derived from the Middle French manufacture ("process of making") which itself originates from the Classical Latin manū ("hand") and Middle French facture ("making"). Alternatively, the English word may have been independently formed from the earlier English manufact ("made by human hands") and facture. Its earliest usage in the English language was recorded in the mid-16th century to refer to the making of products by hand. History and development Prehistory and ancient history Human ancestors have manufactured objects using stone and other tools since long before the emergence of Homo sapiens approximately 200,000 years ago. The earliest methods of stone tool making, known as the Oldowan "industry", date back to at least 2.3 million years ago, with the earliest direct evidence of tool usage found in Ethiopia within the Great Rift Valley, dating back to 2.5 million years ago. To manufacture a stone tool, a "core" of hard stone with specific flaking properties (such as flint) was struck with a hammerstone. This flaking produced sharp edges which could be used as tools, primarily in