Ring is Module over Itself

Theorem
Let $\left({R, +, \circ}\right)$ be a ring.

Then $\left({R, +, \circ}\right)_R$ is an $R$-module.

If $\left({R, +, \circ}\right)$ has a unity, then $\left({R, +, \circ}\right)_R$ is unitary.