title: What is the use case of :host-context selector in angular
body: <p>I've seen an angular course telling that :</p>
  
  <blockquote>
    <p><code>host-context</code> is used to style elements inside a component, depending on some condition set outside of it.</p>
  </blockquote>
  
  <p>I've searched the official documentation for it in <a href="https://angular.io" rel="noreferrer">https://angular.io</a></p>
  
  <p>but it is not documented</p>
  
  <p>can some one explain the different use cases where I can use this selector for an angular component ?</p>
  
  <p>can some one explain the whole meaning of the <code>-context</code> added to host here ?</p>
  
  <p>without an official documentation, does it mean that when someone give one use case, it mean that it is the only case the thing refers to ?</p>