즉시 실행 함수 (self invoking' or 'immediately invoked' function

(function($, window, document)
{
...
...

})(jQuery, window, document);

dd(jQuery, window, document);

It's called a 'self invoking' or 'immediately invoked' function. It means that the function is run as soon as it is created using the parameters in the final set of brackets.
즉시 실행 함수.