When you validate a form using JavaScript, you might need to create a function which handles each input field and checks whether it has the correct form of input. On the other hand, JQuery simply uses the ".validate" plugin. Just start declaring the plugin with all the details (like the fields which are required or maybe a field that is an email, etc.) inside the block and propose a success event. That's all! Form validation on the browser-side is one of the most realistic and efficient usage of JQuery.
Other than this, there are a few more which can prove to be helpful in your web development career. Next in the queue is HTML element properties. Say, for example, you want to show or hide a particular HTML element (a div, a text field or maybe even a block of text that changes); you can do that easily with jQuery. There are functions for HTML and CSS that allow anything and everything to be altered. So, you could just fade out or fade in your required structure. Often this becomes very handy because user interaction is enhanced highly. Closing popup dialog boxes or showing text boxes on click of a button - these tasks become very easy.
Then we have the AJAX database update. With JQuery and PHP at the back-end, we could establish a fantastic task. You have obviously been through Google, Twitter and Facebook. The button functions they use for example, the like button, the tweet button, etc. are made from AJAX functionality. Your data gets stored into the database without navigation. It is very simple to understand and implement and would add great credibility to your website.
Next we have the LOAD function of JQuery. This function has a very good functionality in terms of reducing server load. Suppose your website has to deal with multiple feeds from other webpages. You constantly need to feed fresh data into a particular section of your webpage. Now, if you do this in the generic form of reloading your webpage every 2 seconds for example; your website crashes! JQuery solves the issue by asynchronously loading the webpage contents on your specified panel. Since the data is fetched asynchronously, the page is not refreshed. So, your server bandwidth and load time is saved.
The last but not the least is the "change" function. This function records the state change of the element with which it has been bound. So, when the state changes, it triggers a call-back function to execute some steps that you specify. This comes very handy in terms of inputs. Suppose you have a file input. When the user finishes selecting the file, the call-back function automatically fires the upload procedure.
http://ezinearticles.com/?Five-Most-Simple-Applications-of-JQuery-for-Your-Website&id=7731744