What is the difference between structured concurrency and unstructured concurrency?

Structured concurrency ties lifecycle of tasks to scopes; unstructured concurrency does not.

Structured concurrency ensures all coroutines launched within a scope are completed or cancelled together, preventing leaks and orphan tasks. Unstructured concurrency (like GlobalScope) allows tasks to live independently, which can lead to resource leaks, unpredictable execution, and crashes in lifecycle-bound systems like Android.