What's the difference between using Require.JS amd simply creating a <script> element in the DOM?

My understanding of Require.JS is that it offers the ability to load dependencies, but can this not simply be done by creating a <script> element that loads the necessary external JS file?

For example, lets assume I have the function doStuff(), which requires the function needMe(). doStuff() is in the external file do_stuff.js, while needMe() is in the external file need_me.js.

Doing this the Require.JS way:

define(['need_me'],function(){

    function doStuff(){

        //do some stuff

        needMe();

        //do some more stuff

    }

});

Doing this by simply creating a script element:

function doStuff(){

    var scriptElement  = document.createElement('script');

    scriptElement.src = 'need_me.js';

    scriptElement.type = 'text/javascript';

    document.getElementsByTagName('head')[0].appendChild(scriptElement);



    //do some stuff

    needMe();

    //do some more stuff

}

Both of these work. However, the second version doesn't require me to load all of the Require.js library. I don't really see any functional difference...