Question

explain the process of opening and closing app

Answer 1

THESE WAYS ARE FOR CLOSING
Press the "Recent Apps" button at any time. Most devices running a version of Android newer than 4.0 will have a button that allows you to view and manage recently-opened apps at almost any time. This button is located in the "virtual taskbar" at the bottom of the screen next to the "Back" and "Home" buttons — it looks like two overlaid rectangles. Press this button to begin. The Recent Apps button should be accessible at nearly any time along with the other two buttons in the virtual taskbar. However, if an app is preventing it from opening, try hitting the "Home" button to return to the home screen and try again.For certain Android phones, like the Samsung Galaxy S4, you may need to press and hold the "Home" button until the recent apps list displays.

Swipe the app you want to close. You should see a list containing all of the apps that you've recently launched that are running in the background. To close a task, press your finger on it and use a swiping motion to send it off the side of the screen. This will remove it from the list. While this method will cause the app to stop whatever it's doing and close, it won't stop certain background processes that you've enabled for the app.[2] For instance, if you close your Twitter app this way, the app will cease to run and any tweets that you were in the middle of typing will go away. However, if you've enabled notifications for the app, you'll still receive them even after doing this.
3 Alternatively, hold down and select "Remove from list." Another option for closing apps from the recent apps menu is to simply tap and hold the item, then select the "Remove from list" option when it appears. This should have the same effect as swiping the app off of the screen
4 To force-stop apps, use the "app info" option. To completely terminate an app and any background processes associate it, one additional step is needed. Find the app you want to close, then tap and hold it. Select the "App info" option from the menu that appears. On the next screen, click the "Force stop" option. Click "OK" when you are asked to confirm your choice. This should cause your app to stop completely — including any background functions that were causing you to receive notifications — until you deliberately open it again.Note that this may cause you to lose any unsaved data in the app and that you may need to re-enter any login details the next time you open it

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