The barrel is a unit of volume used in the oil industry with the symbol bbl.
Oil is more commonly expressed in terms of cubic metres (m³) but in the US and in the economic world (mainly because such a large percentage of the world's oil is shipped to the US) as barrels.
The measurement of the barrel originated in the US at the first oil well in Pennsylvania. There were so many variants of barrel size (including those used for wine and other goods) that the distrust became so prevalent a central and standard barrel size was created. This was finally established in 1872 as 42 US gallons.
The cubic centimetre (or cubic centimeter; US spelling) is a unit of volume and is derived from an SI unit with the symbol cm³.
There are 1000cm³ in 1 litre. 1 cubic inch is equal to 16.38706cm³.
The cubic centimetre is sometimes referred to as cc or ccm - for example when administering drugs in a liquid solution. This is due to its relatively small size.
It is also often used in the 'cc' form to express the size of a petrol or diesel engine and represents the total displacement volume of the engine.