title: Using WIF, what is the difference between audienceUris and realm?
body: <p>We have an ASP.NET application using WIF.  Our web.config file has a section like this:</p>
  
  <pre><code>&lt;audienceUris&gt;
      &lt;add value="https://someapp.mycompany.com/App/" /&gt;
  &lt;/audienceUris&gt;
  &lt;federatedAuthentication&gt;
      &lt;wsFederation passiveRedirectEnabled="true" issuer="https://adfs.mycompany.com/adfs/ls/" realm="https://someapp.mycompany.com/App/" requireHttps="true" /&gt;
      &lt;cookieHandler requireSsl="false" /&gt;
  &lt;/federatedAuthentication&gt;
  </code></pre>
  
  <p>Every example I see both the <code>audienceUris</code> and <code>realm</code> are the same value.  What is the difference between these two?  Do we need them both?</p>