title: what is moz-flex webkit-flex in css?
body: <p>I got a code sample from internet. I use it and it works fine. But I dont understand the working of the code.</p>
  
  <pre><code>#header {
      display: -moz-flex;
      display: -webkit-flex;
      display: -ms-flex;
      display: flex;
      -moz-justify-content: space-between;
      -webkit-justify-content: space-between;
      -ms-justify-content: space-between;
      justify-content: space-between;
      background-color: #ffffff;
      border-bottom: solid 1px rgba(160, 160, 160, 0.3);
      height: 3.5em;
      left: 0;
      line-height: 3.5em;
      position: fixed;
      top: 0;
      width: 100%;
      z-index: 10000;
  }
  </code></pre>
  
  <p>What does moz-flex and webkit-flex stands for?</p>
  
  <p>Thanks,
  Sabarisri</p>