The main differences between launch/join and async/await in Kotlin coroutines are:
launch returns a Job and is used to start a coroutine that doesn't return a result, while async returns a Deferred<T> and is used to start a coroutine that computes and returns a result[1][4][5].
join() is used to wait for a coroutine started with launch to complete, while await() is used to retrieve the result of a coroutine started with async[1][2][3].
If an exception occurs in a coroutine started with launch, it is propagated and can crash the application if not handled. With async, exceptions are stored in the Deferred and must be explicitly handled[4][5].
launch is useful for fire-and-forget tasks that don't need to return a value, while async is better for tasks that compute a result that will be used later[1][4].
