​Closes only the active window. The application remains open.

In case the application allows editing of project plans, for opened project that you’ve changed but not saved, application asks whether you want to save the changes.

Learn more:
ExitSaveSave As
Applies to version 2015 and higher.
Project Plan 365 for:
Online SubscriptionWin PC/ServerWin Web/ServerMac
Project Viewer for:
Win PC/ServerMacWin Web/ServerOnline Subscription