Javascript functions and difference

The two ways to declare a java script function:

var functionOne = function() {
    // Some code
};

function functionTwo() {
    // Some code
}

The difference is that functionTwo is defined at parse-time for a script block, whereas functionOneis defined at run-time. For example:

<script>
  // Error
  functionOne();

  var functionOne = function() {
  }
</script>

<script>
  // No error
  functionTwo();

  function functionTwo() {
  }
</script>