What is the role and purpose of the Job object in Kotlin's coroutines system?

The Job object in Kotlin Coroutines represents a controllable task that can be canceled and tracked. It is used to manage the lifecycle of a coroutine: allowing cancellation of execution, checking its status (whether the coroutine is active, completed, or canceled), and linking multiple coroutines into a hierarchy.

For example, when launching a coroutine with launch, a Job object is returned, which can be used to cancel the coroutine:

val job = CoroutineScope(Dispatchers.Default).launch {
    // some work
}

// later
job.cancel() // cancel the coroutine

Thus, Job is a tool for managing and controlling asynchronous tasks in Kotlin.