title: What is the difference between ViewEncapsulation.None and :host, :host /deep/?
body: <p>I have an Angular 6 custom form control which I have created as a wrapper around another control so that we can apply our own css rules.</p>
  
  <p>I have removed the <code>ViewEncapsulation</code> on this wrapper component so that we can hook on to the css classes generated by the existing form control and overwrite the rules.</p>
  
  <pre><code>encapsulation: ViewEncapsulation.None
  </code></pre>
  
  <p>A reviewer suggested me to use the combination of <code>:host</code> and <code>:host::ng-deep</code> rather than using <code>ViewEncapsulation.None</code>.</p>
  
  <p>I don't know why that could be better. Can someone explain?</p>