Define prod

Production function is the relation between physical input such as labour, capital and physical output of a good. It is expressed in the following form: q = f (x1, x2). It means by using x1 amount of factor 1 and x2 amount of factor 2, you will be able to produce q amount of good.

OR

Costs are the total of expenditure incurred by the producer in producing a good. It includes the cost of factor inputs and non-factor inputs of the production of a good.