The cubic foot is a unit of volume in the imperial unit system with the symbol ft³.
1 cubic foot is equal to 1/27 yd³ or 1728 in³. It is equal to the volume of a cube measuring 1ft on each side.
One cubic foot of water weighs 62.4 lbs or 28.29 kg.
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.