How does Task.sleep differ from asyncAfter?

Middle PRO

The essence

Task.sleep(for:) — an asynchronous pause inside the current task. The task suspends, the thread returns to the pool; after the pause the code continues from the same place, on the same isolation. The pause is cancellable: if the task is cancelled, Task.sleep immediately throws CancellationError. It works in any task — structured or created via Task { }.
DispatchQueue.asyncAfter(deadline:) — GCD schedules a closure on a queue no earlier than the given time. The caller continues immediately; the closure is a separate unit of work outside the task tree, with no cancellation (unless wrapped in a DispatchWorkItem and cancel()ed before it starts) and no inherited isolation/priority.

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