Where should i write class name here? in all div's?

Tell us what’s happening:
where should i write class name here?

in all div’s?

Your code so far

<script>
  $(document).ready(function() {
    $("button").addClass("animated bounce");
  });
  $(".well").addClass("aniamtedshake");
</script>

<!-- Only change code above this line. -->

<div class="container-fluid" class= "well">
  <h3 class="text-primary text-center">jQuery Playground</h3>
  <div class="row">
    <div class="col-xs-6">
      <h4>#left-well</h4>
      <div class="well" id="left-well">
        <button class="btn btn-default target" id="target1">#target1</button>
        <button class="btn btn-default target" id="target2">#target2</button>
        <button class="btn btn-default target" id="target3">#target3</button>
      </div>
    </div>
    <div class="col-xs-6">
      <h4>#right-well</h4>
      <div class="well" id="right-well">
        <button class="btn btn-default target" id="target4">#target4</button>
        <button class="btn btn-default target" id="target5">#target5</button>
        <button class="btn btn-default target" id="target6">#target6</button>
      </div>
    </div>
  </div>
</div>

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36.

Link to the challenge:
https://www.freecodecamp.org/challenges/target-elements-by-class-using-jquery

I’m not sure I understand your question, but aniamtedshake should be animated shake.