Async Pipe for Observables and Promises

The async pipe automatically subscribes to Observables or Promises in templates and returns the latest value.

<p>{{ observableData$ | async }}</p>
<p>{{ promiseData | async }}</p>

In Angular 21, with zoneless apps and signal‑based change detection, the async pipe works predictably and efficiently without requiring zone.js.

Note: The async pipe simplifies async data handling in templates and avoids memory leaks by handling unsubscription automatically.