In the metric system, liter or litre is the basic unit of capacity or volume. Liter can be used in order to measure the amount of liquid an object can hold.
1. The figure below shows a bottle that can hold about 1 liter of oil or 1 liter of water if you put water in the bottle instead.
2. The size of a car engine is measured in liters and the size refers to the amount of fuel and air that can be forced in the cylinders. For example, if the manufacturer says that the size of the engine is 2.0 liters, it means that the cylinders have a volume of 2.0 liters.