Like the App Store, your device perpetually checks for new software updates in the background. When one is available, you see a red badge appear on the Settings app; to download it, open the app and navigate to General -> Software Update. There, you see some brief information about the update and a button to install it. You can also force the system to check for an update by navigating to the Software Update pane.
Because these iOS updates are "delta updates" (they contain only the parts of the system that have changed, so you don't have to download the entire system each time there is an update), they're smaller; therefore, you can download them just about anywhere you have a decent 3G or Wi-Fi connection--on the bus, at home, walking down the street, you name it. To install these updates, however, you need to have at least 50 percent battery life on your device, or have it plugged into a power source.
Just as a friendly reminder: Even though you can install these updates anywhere, you should always (always, always) back up your device before you do. You can use Wi-Fi Sync to back up to your computer, or, if you have iCloud Backup enabled, you can use that. (See the "Work in the Cloud" section later in this chapter for more information on iCloud Backups.)
Install updates from your computer: Maybe you're not that adventurous, and you'd prefer to install your software update the old-fashioned way. No problem: Just connect your device to your computer and check for updates in iTunes. (If you're using Wi-Fi Sync, you can also do this by plugging your device into a power source and connecting it and your computer to the same Wi-Fi network, and then opening iTunes.)
Serenity Caldwell is a Macworld staff editor.
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