JavaScript

One of the biggest problems with writing software that works in a web browser is that the code needs to run on the server, this means the web browser has to send its information back to the server and wait for a new page to be sent back. This is why when you use web applications you constantly get a 'page refresh' everytime you click on a button, or perhaps select an item from a list.

This doesn't really make for a great user experience and in many cases the information sent back and forth is actually pretty small, as such the use of a web server is actually not always necessary if the web browser could do some of the processing itself.

In the middle nineties, Netscape (of course once the King of web browsers) decided to create a programming language that would run inside their web browser, Netscape Navigator. Although it wasn't initially called JavaScript, it was renamed as part of the 'Java trend' when, for some bizarre reason, everyone went Java mad!

So how does it work? When you view a webpage that contains some JavaScript code it is ignored by the web server and left inside the page that the browser receives. If the web browser supports JavaScript, and they all do today pretty much, it will read the code and run it after receiving the page.

Today we tend to use JavaScript to improve the overall user experience and to reduce the amount of 'page refreshes' (or 'postbacks' as they are correctly referred to as). So whenever you click on something on a page and the page doesn't postback you will know that JavaScript has been involved.

To prove how much JavaScript is being used today, turn it off in your web browser and browse your favourite websites and you will notice the difference.