What setTimeout Really Does in Angular
In JavaScript, setTimeout queues a task on the macrotask queue to be run after the current call stack clears. In a normal JS app, this is predictable.

But Angular isn’t just JavaScript — it uses Zone.js under the hood.

Zone.js monkey-patches setTimeout so Angular can trigger change detection after async operations.

Every time setTimeout fires, Angular knows something changed. So it runs its entire component tree check cycle.