When a coroutine is created using the launch builder, the return value is an instance of Job. We said earlier that this type of coroutine is used when we don't care about computing a result, and that is true. However, we still may require access to the life cycle of the coroutine.
We can think of coroutines conceptually like a thread, in that they have some code to execute and are created, started, and eventually complete with either a successful result or some failure, or are canceled prematurely as they are still executing. A job instance allows us access and control over this life cycle just as a Future would in a program that works at the thread level.