Is there a name to $[R:I]$ in Ring Theory?

Question

I was solving problems related to elementary Ring Theory and I came across this question:

Let $I$ be an ideal of $R$. Define $$[R:I] = \{x\in R : rx\in I, \forall r\in R\}$$ Show that $[R:I]$ is an ideal of $R$.

Is there a name to $[R:I]$ ? If yes, how can I know more about it? It sounds interesting.