jQuery is a fast, small, and feature-rich client side JavaScript library.
Makes things like HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers.
Whenever html manipulation is needed. Issuing ajax requests registering for DOM events, etc.
When building sophisticated single page web applications.
For this kind of tasks a more elaborate client library will be needed like KnockoutJS, Backbone or AngularJS.
A lot of resources in the jQuery site
A good set of examples can be found at:
Example 1 -Hide an element with id "textbox“
//javascript document.getElementById('textbox').style.display = "none"; //jQuery $('#textbox').hide();
Example 2 - create a <h1> tag with "my text"
//javascript var h1 = document.CreateElement("h1"); h1.innerHTML = "my text"; document.getElementsByTagName('body')[0].appendChild(h1); //jQuery $('body').append( $("<h1/>").html("my text") );
// dissapearing links $( "a" ).click(function( event ) { event.preventDefault(); $( this ).hide( "slow" ); });
$.get( "myhtmlpage.html", function() { // issues an AJAX http get for the myhtmlpage.html file });