There are some advantages of linking to JQuery on Google like : 1- Faster Loading time ( As the JQuery file may be cached at your browser because others website you may already visited using it ) 2. Second getting the latest version automatically.
The syntax of JQuery is as follows :
for example :
$("p").hide() // Hide all paragraphs
$(".divA").hide() // Hide all html elements with class .divA
So in brief, with JQuery you will be selecting html elements from the current document and doing some actions on it, important hint before you start that you should wait until the document is loaded before you start JQuery actions and this is handled by calling ready function :