The short run means a period of time within which the firms can alter their level of output only by increasing or decreasing the amounts of variable factors such as labour and raw materials, while fixed factors like capital equipment, machinery etc.
The long-run equilibrium point for a perfectly competitive market occurs where the demand curve (price) intersects the marginal cost (MC) curve and the minimum point of the average cost (AC) curve. In the long-run, economic profit cannot be sustained. (LumenLearning)
