UK Barrels
A UK barrel is 36 imperial gallons (not to be confused with American gallons), about 163.659 liters or 0.163659 cubic meters. It is based on the traditional wine barrel used in the United Kingdom.
Metric cups
Metric cups are used in cooking and baking to measure ingredients such as flour and sugar. One metric cup is 250 milliliters or a quarter of a liter.