title: What is the difference between reading session id, from cookie or request?
body: <p>When you use session in <code>cookieless="false"</code> mode in <code>web.config</code>, it stores session id in a cookie value (I mean <code>aspnet_sessionId</code>). I want to know if by any reasons session id changes this cookie's value will update automatically or not?</p>
  
  <p>And what is the difference between reading user session id by these two statements:</p>
  
  <pre><code>System.Web.HttpContext.Current.Session.SessionID  
  </code></pre>
  
  <p>vs</p>
  
  <pre><code>Request.Cookies["Aspnet_sessionId"].Value  
  </code></pre>