The stere is a unit of volume and is a non-SI unit but accepted for use as a metric unit with the symbol st.
1 stere is equal to 1 cubic metre (1 m³) which is equivalent to the volume contained in a cube with edges all at 1 m. The stere is used to measure large quantities of cut wood or firewood. It is used to distinguish between cut and uncut wood - its equivalent, the cubic meter is used to measure uncut wood.
The word 'stere' hails from the Greek 'στερεός' or 'stereos' which translates to 'solid'. It represents the wood used to produce the cut wood - and therefore often the dimensions of the cut wood is less than its uncut equivalent.
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.