A topological space is said to be totally disconnected space if any pair of distinct of can be separated by a disconnection of .

In other words, a topological space is said to be totally disconnected space if for any two points and of , there is a disconnection of such that and .

In other words, a topological space is said to be totally disconnected space if its connected subsets are only the singleton subset of .

**Example:**

Every discrete space is totally disconnected.

Let be a discrete space. Let , then and are open subsets of such that . Since is a disconnection of , so is totally disconnected.

**Examples:**

• One point space is totally disconnected.

• is totally disconnected.

• is totally disconnected.

• The Cantor set is totally disconnected.

• with usual topology is not totally disconnected.

• with upper limit topology generated by open-closed intervals is totally disconnected.

**Theorems:**

• Every totally disconnected space is Hausdorff space.

• The components of a totally disconnected space are its singleton subsets.

• If a Hausdorff space has an open base whose sets are also closed then is totally disconnected.