In the long run, all factor inputs are variable. This means that a firm can adjust its usage of all inputs including labor, capital, and materials to produce a desired level of output. Unlike in the short run, where at least one input is fixed, in the long run, a firm has the flexibility to choose the optimal combination of inputs to minimize costs and maximize profits. This makes the long run a crucial period for firms to make strategic decisions such as expanding production, entering new markets, or investing in new technology to stay competitive.