Understanding Angular data binding
<p>While reading <a href="https://angular.io/docs/ts/latest/guide/architecture.html" rel="nofollow">Angular 2 documentation</a>, I came across this (emphasis mine)</p>

<blockquote>
  <p>Angular processes all data bindings <strong><em>once per JavaScript event cycle</em></strong>, from the root of the application component tree through all child components.</p>
</blockquote>

<p>Please explain in as much detail as possible what this means? Especially what is "once per event cycle"?</p>