# Definition
If there are two points $x$ and $y$ in a [[Topological Space|topological space]] $X$ that can be separated by neighbourhoods if there exists a neighbourhood $U$ of $x$ and a neighbourhood $V$ of $y$, such that $U$ and $V$ are disjoint $U \cup V = \emptyset$.

$X$ is a **Hausdorff space** if any two distinct points in $X$ are separated by neighbourhoods.