If you are running into javascript issues and the jQuery Easy plugin does not seem to fix anything, this may be due to several factors:

You do need to setup the Migrate plugin if you are running jQuery prior to the 1.9 version.

jQuery and MooTools both are feature-rich javascript libraries used by developers to traverse and manipulate HTML documents in a simpler and more convenient way than the Document Object Model or DOM (which is the original API supported by all browsers) can provide.

A Content Delivery Network or CDN is a globally distributed network of highly optimized servers deployed in multiple data centers. It serves end-users closest to those centers therefore delivering content with high availability and high performance.

Many JavaScript libraries (like MooTools, which is loaded as part of the Joomla! 2.5 framework but phasing out in Joomla! 3) use $ as a function or variable name, just as jQuery does. In jQuery's case, $ is just an alias for jQuery, so all functionality is available without using $ and can be replaced with jQuery.