When you exit an app simply by opening another one, the first app is still "running" in the background. Most apps do not update during this "backgrounded" or dormant mode, although they are still using active memory space. For apps that receive periodic updates from wireless services or the internet, this can give the appearance that the app's data is out-of-date or that the app has malfunctioned. The best procedure to avoid these issues is to "Force-Close" an app when you are not actively using it.
The actual process varies with the operating system.
For iPhone 10 and higher:
To see what apps are running in the background on an iPhone 10 or newer device, you can swipe up from the bottom of the screen and you will see the apps appear. You can then swipe up from the bottom of the app to force-close it.
For older iOS devices:
When you tap the "Home" button while viewing an app, the app will go into "background" or "dormant" mode, and not be the primary app visible on the screen.
Selecting the app-icon on the Home Screen of the device will simply re-open the app in the last state it was in, and with the last data downloaded to the app.
To Force-Close the app:
- Double-Tap> the "Home" button to bring up the windowed-apps
- Swipe Left/Right to locate the app you want to Force-Close.
- Tap-and-Hold> on the app, and "sweep" it "Up and Away".
The next time you open the app it will launch as a "fresh start" and update any data.