jQuery integration in SharePoint

This blog may be very simple but it really useful to understand "How to integrate the jQuery  in SharePoint WebPart or SharePoint Application Page"

First approach
You can use the Module to include the jQuery file if you developing the "Sandbox" solution and refer the file path in script tag.

Second approach

In farm solution,you can include the jQuery file in _layout folder and for best practice create the "1033" folder inside the _layouts and refer in script tag.
Here you can use the SharePoint Script Link control also


Instead of using Google or Microsoft hosted CDN you can download the file and host in your local sharepoint server.