title: jquery ajax call async: true vs async:false
body: <p>In my chrome extension i used jquery library and this is my post ajax request but i am confuse is it synchronous request or asynchronous ?</p>
  
  <pre><code>  $.ajax({
              type: 'POST',
              url: "https://api.xxx",
              data: { domain: b },
              cache: false,
              success: function (data)
              {
                  var response = JSON.parse(data);
                  .......
                  if () 
                  {
  
                  }
                  else
                  {
  
                  }
              },
              error: function (data)
              {
                  $('.popup').html("test");
              }
          });
          return $ret;
      }
  </code></pre>
  
  <p>if it is synchronous is it enough to add </p>
  
  <pre><code>async:true
  </code></pre>
  
  <p>to make it asynchronous?</p>
  
  <p>NB: I have another GET request. thing is POST request is working pretty fine but during get request the response is really slow sometimes i had to make several click or reload to make it work.</p>