A capital good is a durable good (one that does not quickly wear out) that is used in the production of goods or services. Capital goods are one of the three types of producer inputs, the other two being land and labor, which are also known collectively as primary factors of production. In the study of economic systems and in Marxian economics, the term means of production is often used with the same meaning as capital goods. This classification originated during the classical economic period and has remained the dominant method for classification.