What is jQuery(document) vs. $(document)

I don't get what jQuery(document) is here. I thought you always used $(document)

see here in his examples: http://sorgalla.com/projects/jcarousel/

There is no difference. $ is shorthand for jQuery. Sometimes $ is disabled as it may conflict with other Javascript libraries you are using. It is otherwise identical.

jQuery uses $(). Prototype uses $(). AFAIK Mootools uses $(). If that was the end of it, it would be impossible to use any combination of the three. So responsible frameworks provide a way to disable $() to avoid conflicts and use something else instead. In jQuery's case, that's jQuery().

jQuery() is recommended over $() for use in jQuery plugins, so they keep functioning if you do disable $().

It's like <? versus <?php: one is a shorthand version that may be vulnerable to conflicts.

The $ is just a shortcut for JQuery.