The cup is a unit of volume in the US customary unit system with the symbol cup.
It is equal to 1/2 US customary pint, 1/4 US customary quart and 1/16 US customary gallon. it is also equal to 236.5882365 millilitres.
Used primarily for cooking - the cup was adopted and established as a recognised unit of measure as it could be used by almost anyone in any kitchen. Due to the slight variants in design and size, it is rarely used as an accurate measure for important or critical materials, however it does represent a specific amount and can be used across many recipes to indicate what is needed.
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.