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 is connected to a float mechanism inside the fuel tank, which moves up and down as fuel is consumed. Most fuel gauges have markings that represent full, half, and empty levels. When the fuel level drops, the gauge moves accordingly, providing a visual representation of how much fuel is left. This information is crucial for maintaining the vehicle's operation and preventing running out of fuel unexpectedly.