A litre is a unit of measurement. You measure small amounts of liquid in millilitres (ml), while greater volumes are measured in litres. Juice often comes in 1 litre bottles and so do things like ...
Units from the metric system can be used to describe the mass, volume or length of an object. Mass is measured in grams (g) and kilograms (kg). Volume is measured in millilitres (ml) and litres (l).