title: SignInManager,what it is and how,when to use?
body: <p>I am exploring SignInManager class. But the information given on MSDN is very useless. It only tells what are the methods and properties provided.</p>
  <p>What I am looking for is,</p>
  <ol>
  <li>What is SignInManager?</li>
  <li>How to use it?</li>
  <li>And I have my own database that contains credentials related info(username and passwords)</li>
  </ol>
  <p>How can I use SignInmanager and how to use it so my custom database is used for authenticating users?</p>
  <p>I am using asp.net MVC 5 and Visual Studio 2015. In my sample project I have accounts controller that contains action methods like</p>
  <pre><code>  public async Task&lt;ActionResult&gt; ExternalLoginCallback(string returnUrl)
  </code></pre>
  <p>But I have no idea how to use it, MSDN is completely useless to provide info on this. Any helpful links that explains it in details because I have no idea what SignInManager is and what it's for.</p>
  <p>Thanks</p>