What do you mean by production function?

The relationship between the amount of input required and the amount of output that can be produced with the help of them is called the production function. It specifies the maximum output that can be produced with a given quantity of inputs for a given level of engineering or technical knowledge.

Let, a firm produced only one type of output with two inputs (L, K). Thus, the general equation of this simple production function is Q=f(k, L)---------(i)

Eqn (i) reads: the quantities of output is a function of or depends on the quantities of labor and capital used in production.