title: Angular - Difference between "optimization" and "buildOptimizer" in the build config (angular.json)
body: <p>Can someone explain me exactly the difference between those two flags (<code>optimization</code> and <code>buildOptimizer</code>) defined in the build config <code>angular.json</code> during the build process when I execute <code>ng build</code>?
  The official <a href="https://angular.io/cli/build" rel="noreferrer">build documentation</a> isn't clear to me.</p>