If the quiet hours option is activated, the number of notifications automatically disappears and a crescent would appear on the bottom right part of the speech bubble. If there are no notifications, then it would be a completely black speech bubble without anything in it. Now, it is located next to the date & time button and it looks like a white speech bubble with black lines. It only looks like this when there are notifications. The Action Center button was originally located to the left of the date and time button, and the speech bubble was black with white lines. By default, in desktop, 4 quick settings are shown, but the rest are shown when the 'Expand' button is clicked. Including quick settings which can all optionally appear in the action center.Getting notifications from emails and others.

The Action Center has the following features: The Action Center replaces the charms in Windows 10. It was first introduced with Windows Phone 8.1 in July 2014, and was introduced to the desktop with the launch of Windows 10 on July 29, 2015. The Action Center is a type of notifications system that is available in Windows 10 for laptops, Windows Phone 8.1 and Windows 10 Mobile for mobile devices.

Microsoft surface action center