Production is the process of combining various inputs, both material (such as metal, wood, glass, or plastics) and immaterial (such as plans, or knowledge) in order to create output. Ideally, this output will be a good or service which has value and contributes to the utility of individuals. The area of economics that focuses on production is called production theory, and it is closely related to the consumption (or consumer) theory of economics.
The production process and output directly result from productively utilising the original inputs (or factors of production). Known as land, labor, capital and entrepreneurship, these are deemed the four fundamental factors of production. These primary inputs are not significantly altered in the output process, nor do they become a whole component in the product. Under classical economics, materials and energy are categorised as secondary factors as they are byproducts of land, labour and capital. Delving further, primary factors encompass all of the resourcing involved, such as land, which includes the natural resources above and below the soil. However, there is a difference between human capital and labour. In addition to the common factors of production, in different economic schools of thought, entrepreneurship and technology are sometimes considered evolved factors in production. It is common practice that several forms of controllable inputs are used to achieve the output of a product. The production function assesses the relationship between the inputs and the quantity of output.