title: How does MediatR know which handler to call?
body: <p>I'm learning MediatR and I have a problem connecting the Controller to the Handler.</p>
  <p>Controller:</p>
  <pre><code>[HttpGet]
  public async Task&lt;List&lt;PersonModel&gt;&gt; Get()
  {
      return await _mediator.Send(new GetPersonListQuery());
  }
  </code></pre>
  <p>My understanding is that the Controller will invoke the Handler using <code>_mediator.Send()</code>. However, the argument for Send is not the Handler but the <code>Command</code> / <code>Query</code>.</p>
  <p>In Visual Studio, I checked how many reference there are to the Handler and it says Zero. So how does the MediatR know which particular handler to call?</p>
  <p>Thanks.</p>