The difference between jquery (function () {}) and (function () {}) (jquery)

share some of the lessons learned when developing jquery plugins.  
first, look at

jQuery (function () {
});  
all written as
jQuery (document). Ready (function () {
      
});  

The meaning is that the ready () method is executed after the DOM has been loaded.  
second, look again

(function () {

}) (jQuery);
It is actually an anonymous method of executing () (para), except that the jquery object is passed.  

iii. Summary

jQuery (function () {}), which holds the code for manipulating the DOM object, and the DOM object already exists when the code executes it. cannot be used to store code that develops plug-ins, because jquery objects are not passed, and external methods (functions) cannot be called by Jquery.method.