Summary:
Multitasking is a feature of iOS that allows applications to perform specific tasks in the background while you are using another application. This article explains which features use multitasking, how to switch between apps, and how to troubleshoot multitasking.
Multitasking in iOS allows you to switch instantly between apps and to resume an app. When you return to an app, you can pick up right where you left off. Multitasking doesn't slow down the performance of the foreground app or drain battery life unnecessarily.
Understanding Multitasking and recently used apps:
Double-clicking the Home button displays a list of
recently used apps. These apps are not necessarily actively in use or open. Most applications are not taking up system resources when running in the background and instantly launch when you return to them.
Certain tasks or services can continue to run in the background, and you can determine most by checking the status bar