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 cubic yard is a unit of volume derived from the imperial system of units. It uses the symbol yd³.
It equals the volume of a cube with edges that each measure 1 yard. It is equivalent to 27 ft³, 46656 in³ or ≈ 0.764554 m³.
The yard (and derivatives like the cubic yard for example) are the same in both the imperial systems and US customary systems so require less conversion systems to calculate / convert to SI or metric.