Edit in JSFiddle

var $tasks = $('#tasks li');

var $task = $tasks.find('.task');
var $task2 = $tasks.filter('.task');


alert("using find: " + $task.attr("class"));
alert("using filter: " + $task2.attr("class"));

<ul id="tasks">
    <li class="task">Do some work</li>
    <li class="task">Do more work</li>
    <li class="relax">Relax!</li>
</ul>