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.