JavaScript completes the current synchronous work before running queued Promise reactions. Calling then schedules a reaction; it doesn't run the callback immediately. Await also suspends the continuation even when its Promise is already fulfilled. A reaction that schedules another reaction adds new work behind jobs that are already queued. These rules explain the small output-prediction traces in this lesson. You will create the traces by executing real callbacks and compare their returned order. The lesson covers Promise jobs in this worker environment. It doesn't claim that browser rendering, Node event-loop phases, or unrelated host callbacks follow one universal order. Trace enqueue time separately from callback execution time.