To edit the folder itself, its name, contents, or the layout of the apps inside, you can either enter edit mode and then tap the folder, or, while the folder is open, tap and hold any icon inside. You can then tap the folder’s name to change it, drag apps within the folder to rearrange them, drag an app out of the folder to return it to the Home screen, or tap an app’s Delete button to completely delete it from your device. Unlike apps, folders don’t have a Delete button; to delete a folder, you must remove all the apps from it.
Manage folders from iTunes: iTunes has long allowed users to manage installed apps when syncing, and you can edit your folders too, using your mouse and keyboard. When your device is connected to your computer, the Apps tab in iTunes lets you choose which apps to sync, as well as decide how to organize these apps. Drag an app onto another app and, after a slight delay, a folder is created—just as if you’d performed the same action on your device. You get the same editable folder name, and you can rearrange icons within the folder. Since you’re using a computer, you don’t need to click and hold to enter the jiggling-icon edit mode; you can click and drag anytime. Similarly, to edit an existing folder, just double-click it.
Multitask on your iOS device
Opening and closing an app is easy: Tap the app to open it, and then press the Home button to close it. But when you exit, you’re not actually shutting down the app: You’re freezing it in place, or sending it to run in the background. This means you can have multiple active apps running at any one time, and you can even switch between active apps without returning to the Home screen.
Frozen apps versus background apps: Sometimes you need an app to keep doing something when it’s not in the foreground. For that reason, Apple allows apps to perform tasks in the background using several tools. One of these tools is the push-notification system; another allows music apps to keep playing while the user switches to another app; yet another allows tasks, such as photo uploads, to continue running in the background even if you switch out of the program performing the upload. If your third-party app doesn’t incorporate one of these background features, it will “freeze”, which is to say it will remember whatever you were just doing when you re-open it, but will not process any data in the background.