While looking at some graph theory questions, I came across a set construction and was wondering if there is a name for it.
A subset of vertices $S \subseteq V$ such that for every vertex $u \in V - S$ there exists a vertex $v \in S$ such that $uv \in E$.
Or, as I understand it more intuitively, each vertex not in this set has an adjacent vertex in this set.
It's called a dominating set.