title: Apache Bench: Mean vs Mean across all concurrent requests
body: <p>What is the difference between those 2 fields? :</p>
  
  <ul>
  <li>Time per request (mean)</li>
  <li>Time per request (mean, across all concurrent requests)</li>
  </ul>
  
  <p>How is each of them calculated?</p>
  
  <p>Sample Output:</p>
  
  <pre><code>Time per request:       3953.446 [ms] (mean)
  Time per request:       39.534 [ms] (mean, across all concurrent requests)
  </code></pre>
  
  <p>Why is there much difference?</p>