The economist's distinction between the long run and the short run captures the idea that quantities of some factor inputs can be varied in the short run but not in the long run.

Factor Inputs

The resources used in the production of goods and services, such as labor, land, and capital.

Long Run

A period in economics where all factors of production and costs are variable, allowing all inputs to be adjusted.

Short Run

A period in which at least one factor of production is fixed, limiting the ability of a business to expand its output.