Scale of Economies.

Economies of scale  :- Refers to reduced costs per unit that arise from increased total output of a product.

or

Economies of scale is about increasing the size of a business to make cost saving.

Example :- Suppose if we talk about manufacturing industry , if factory "A" uses only man power to make bread with hand and factory "B" uses machines to produce bread totally with machinery. So the total cost of production is obviously higher in factory "B" but the average cost of production is lower in "B".