Symbolic power of a prime ideal

Definition
Let $$R$$ be a commutative unital ring, $$Q$$ a prime ideal of $$R$$ and $$n$$ a positive integer. The $$n^{th}$$ symbolic power of $$Q$$, denoted as $$Q^{(n)}$$ is defined as the set:

$$\{ r \in R | sr \in Q^n, s \in R \setminus Q \}$$

Equivalently, it is the pre-image of the $$n^{th}$$ power of the localized ideal $$Q_Q$$ in the localization $$R_Q$$.