title: JWT (Json Web Token) Audience "aud" versus Client_Id - What's the difference?
body: <p>I'm working on implementing OAuth 2.0 JWT access_token in my authentication server. But, I'm not clear on what the differences are between the JWT <code>aud</code> claim and the <code>client_id</code> HTTP header value. Are they the same? If not, can you explain the difference between the two?</p>
  
  <p>My suspicion is that <code>aud</code> should refer to the resource server(s), and the <code>client_id</code> should refer to one of the client applications recognized by the authentication server (i.e. web app, or iOS app).  </p>
  
  <p>In my current case, my resource server is also my web app client.  </p>