cube - a solid geometric figure with six identical faces
sphere - a solid geometric figure that can be defined as the limit of all shapes with n identical faces as n -> infinity
a cube is, by definition, the best approximation of a sphere that has 6 sides
also there's a whole load of topology shit I could talk about but imma be honest I don't know shit about topology and I'd end up paraphrasing some 3blue1brown video or something