All coroutines must run within a specific scope which allows them to be managed as groups instead of as individual coroutines. This is particularly important when canceling and cleaning up coroutines, for example when a Fragment or Activity is destroyed, and ensuring that coroutines do not “leak” (in other words continue running in the background when they are no longer needed by the app). By assigning coroutines to a scope they can, for example, all be canceled in bulk when they are no longer needed.
Kotlin provides some built-in scopes as well as the option to create custom scopes using the CoroutineScope class. The built-in scopes can be summarized as follows:
•GlobalScope – GlobalScope is used to launch top-level coroutines which are tied to the entire lifecycle of the application. Since this has the potential for coroutines in this scope to continue running when not needed (for example when a Activity exits) use of this scope...
