In this chapter, we started moving away from classical web development for the first time. We introduced jQuery, a powerful JavaScript library that allows us to write cleaner and more compact JavaScript code. Moreover, it is going to be easier for us to do so, as it uses CSS style selectors to specify DOM elements, rather than JavaScript methods that we would have to learn.

How to download and where to place the jQuery library was explained. We illustrated the remainder of the chapter with examples using jQuery's most useful and powerful methods. To conclude the chapter, we introduced the jQuery way of creating event handlers, possibly the most important concept to grasp at this stage of the book.

In the next chapter, we will continue to use jQuery, not to traverse the DOM and change a little bit of content here and there, but to generate entire chunks of our page on the Web server by executing PHP code that is called using jQuery methods. Then we can use the data to update parts of...