The four main components of production are labor, land, capital and entrepreneurship as defined by Adam Smith. Labor refers to amount of work put into the production. Productivity is an index of how good the production performs. Land refers to the space. This is where the other element: labor is located. It is a passive element and the least important one among the factors. Capital is the starting investment to put up the production and lastly entrepreneurship is the technique used to sustain the business.Entrepreneurs are so called the agents of growth. These ideas are all included in Adam Smith's Theory of Development in Economics.