title: NSURLSession has NSoperationqueue internally?
body: <p>A)If NSURLSession runs task in background in iOS7,Has Apple integrated internally Queue in NSURLSession?How it works in secondary thread and also in App suspended Mode?</p>
  
  <p>B)What is the difference between NSURLSession and  NSoperationqueue?</p>
  
  <p>C)If NSURLSession is the replacement of NSURLCOnnection, Can we integrate NSURLSession into 
  NSOPerationqueue?</p>
  
  <p>D)Are both same?</p>
  
  <p>E)Can we do the same thing in NSURLSession as in NSoperationQueue?</p>
  
  <p>f)is there any time limit to do task in background after closing application? because iOS7 does 2 min while ios6 does 10 min?</p>
  
  <p>G)
  <a href="http://www.objc.io/issue-5/multitasking.html" rel="nofollow">Tutorial</a> says under section Configuration and Limitation,NSURLSessionDataTasks are not supported in background sessions at all, and you should only use these tasks for short-lived, small requests, not for downloads or uploads.some tutorials are telling there is no time limit, we can download or upload data,the size may be whatever..Please explain more on this?
  If NSURLSession is the relplacement of NSUrlconnection ,Which one is the best in all situations?What is the future of NSUrlconnection?</p>