Take this page you're viewing for example. The 'markup' meaning buttons, links, forms, etc are HTML The 'design' of such such as the background, the way the buttons float etc is CSS The 'backend' of such comes from PHP (pulling info from a database before sending it to the browser) The reply form however, with the buttons that behave, or google maps, or when an alert dialog pops up is javascript. In a nut shell its a scripting language that runs on the client side (from your browser instead of from the server) . For the more technical response, there's wikipedia: (It is also important to keep in mind that Java and Javascript are not the same thing, think of Java as more like Flash or ActiveX)
javascript is a scripting language mainly used at client side and also it is added some features and can use to create great look and feel on website.
Javascript is nothing but writing javacode with jsp pages that means doing both the designing and logical coding within the same page. If you need further clarifications you can PM me.
chandusek, you are so wrong it's not even funny. kblessinggr explained it perfectly. It has nothing to do with jsp or java.
Hi , Javascript is a browser scripting language gives help on client side. If you want to learn the basics of it I like to say start with some online tutorials availabe on net, here is one of them might be helpful to , Javascript Tutorial