Notification Center For iPhone : When an app wants to let you know something, it uses Apple’s notifica­tion system. These notifications can be displayed as floating banners, pop-up alerts, or a combination of the two; when you’d like to see all the alerts you’ve received recently, you can check Notification Center.

Banners By default, you receive notifications as banners. These alerts are superimposed along the top edge of your iPhone, rotating into view with a 3D effect. The banners remain on screen for about five seconds. While a floating banner is on display, you can tap it to launch the notify­ing app (such as Twitter, Messages, or Mail). Let’s say you receive a banner notification because someone mentions your name in a tweet: Just tap the notification, and your Twitter client of choice launches to show you the tweet in question.

If you don’t want to attend to a banner immediately, you can ignore it and keep working away in whatever app you’re using. Banners float on top of the screen for several seconds, and they vanish on their own.

Notification Center If you don’t tap a banner in time, or you want to see your past notifications, you can access Notification Center whenever your iPhone is unlocked. Swipe down from the menu bar at the top of your screen; you’ll head right to your device’s repository for notifications.

Notification Center groups your past notifications by app; you can sort those apps by time or sort them manually (you can configure the order you’d like in the Settings app). You can clear out accumulated notifications per app with a pair of well-focused taps: Tap the tiny X next to the app’s name, and then tap the tiny Clear button that appears.

You can choose the number of alerts a given ap can show in Notification Center, though the controls are a bit limited. For example, you can choose how many upcoming Calendar events are displayed, but you can’t choose which calendar iOS pulls those events from.

Notification Center also offers you two optional widgets to stick at the top of the section: Weather and Stocks. You can enable or disable either widget in the Settings app. If enabled, the Stock widget displays a scrolling ticker of any stocks you’ve configured from the Stocks app, and Weather provides current conditions and a forecast for your current location (if enabled) or your primary Weather location. Third-party app widgets are not supported.

Customize Notifications To define precisely how Notification Center and alerts work on an app-by-app basis, head to the Settings app and tap Notifications. You choose which apps notify you, and you can configure all sorts of behaviors. For each app, you can set whether notifications should appear in Notification Center at all; how many items can be displayed there; whether there should be an alert, and if so, which type (banner or pop-up alert); whether to use an icon badge to signify alerts; whether new alerts should include sounds; and whether notifications should appear in your lock screen.

Lock Screen Notifica­tions You can also track your notifications on your lock screen. New notifica­tions stack in the order that they arrived, with the newest on top regardless of which app it’s from—an option that’s not available for Notification Center itself.

From the lock screen, you can swipe to unlock your iPhone, but you can also swipe an individual notifi­cation to directly launch the app associated with it. Note that when a new alert arrives while your device is locked, the standard swipe to unlock still launches the app associated with that just-arrived notification.

When a new notification arrives while your iPhone is locked, it gets special treatment: The alert gets centered in the middle of the screen, a bit like the notifications of old. But other, previously arrived lock-screen notifications are still accessible. A small gray handle appears at the top of the lock screen when other notifications are temporarily hidden from view; drag it down to expose them (with a gesture much like the swipe to get to Notification Center ).

See also:

• How To Use Reminders in iOS 5
• Buying an iPhone | Which model? Where from?
• How To Share Your iPhone’s Mobile Net Connection
• How To Use iPhone 4S | Change Your Settings
• How To Use iPhone 4S | Knowing For Beginners
• How To Share Your iPhone’s Mobile Net Connection