A gas tank is a container designed to hold fuel, typically gasoline or diesel, for vehicles like cars and trucks. It is usually made of metal or plastic and is located underneath the vehicle, often near the rear. The gas tank connects to the engine through fuel lines, allowing the fuel to be delivered as needed for combustion. Most gas tanks have a filler neck where fuel is added, and they are equipped with a cap to prevent spills and evaporation. Some tanks also include a fuel gauge, which indicates the amount of fuel remaining, helping drivers manage their fuel consumption effectively.