通知中心
Notification Center can be accessed by clicking the icon in the right corner of the menu bar. When open, the user can click a button to tweet, post status updates to Facebook, or view all notifications in the sidebar pane. Swiping up will reveal the option to disable Notification Center for one day. Many settings of Notification Center can be customized under the "Notifications" pane in System Preferences. Each application can have three ways to display notifications: none, banners, and alerts. Options to toggle the app icons and sounds are also available. Users can click and drag an app in the pane to change the order the applications are displayed within Notification Center.