A fuel gauge is a device found in vehicles that indicates the amount of fuel remaining in the tank. It typically consists of a dial or digital display that shows the fuel level, helping drivers know when to refuel. The gauge works by using a float that moves up and down with the fuel level, sending signals to the gauge to display the current status. Most fuel gauges are calibrated to show levels from empty to full, often marked with "E" for empty and "F" for full. Some modern vehicles also include a warning light that illuminates when the fuel level is low, providing an additional alert to drivers.