Tree View Instead of QuickLaunch in Sharepoint

There is a Tree View Option built into SharePoint Online ,In order to Enable it do the following Actions

1.Click on Site Actions -> Site Settings
2. Click on "Tree View" under "Look and Feel"
3. Remove the check from Enable Quick Launch and put the check in Enable Tree View.

Once you navigate back to the root site after confirmation you will see that the tree view instead of quick launch.