Why does the Flutter Background_fetch library fail to function once the app has been terminated?

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The Flutter Backgroundfetch library, like most other background execution libraries, relies on the operating system to keep the app running in the background. Once the app is terminated, the operating system stops all background tasks associated with the app, including the tasks triggered by the library. This is a security measure implemented by both iOS and Android to prevent apps from consuming too much battery and processing power in the background. Therefore, the Flutter Backgroundfetch library fails to function once the app has been terminated.