A fan is a device used to create a flow of air. Typically powered by an electric motor, fans use rotating blades to generate this airflow, which can be used for cooling, ventilation, or general air circulation. They come in various forms, from small handheld fans to large industrial models, and are commonly found in homes, offices, and vehicles. Their purpose is to provide comfort by increasing evaporation on the skin, removing stale air, or providing a more even distribution of temperature.