An indicator light is a small light on a device or vehicle that signals a specific condition or status. For example, in a car, an indicator light may illuminate to show that the engine is running low on oil or that the battery is not charging properly. These lights help users quickly identify issues that may need attention. Indicator lights can also be found on household appliances, such as microwaves and washing machines, to indicate when a cycle is complete or when the appliance is in standby mode. Understanding these lights can help users operate their devices more effectively and safely.