Affine hull

The affine hull of a set $$C$$, namely $$\textbf{aff} C$$, is the set of all affine combinations of all the points in $$C$$. Thus, the affine hull is the smallest affine set that contains all the points in $$C$$. Affine hulls are "very big", because affine sets are "very big" (see affine set). That is, non-trivial affine sets include infinite points (e.g., entire lines, planes or volumes)