AJAX stands for Asynchronous JavaScript And XML. Basically, what we can do is use JavaScript to load data into the page after it has loaded. This is a great way to generate a graph based on user interaction. In this chapter, we'll use AJAX to build a bar graph. By the end of the chapter, you should be able to do the following:

• Use AJAX to make an asynchronous call to an external data file
• Create a bar graph

The complete code for this section can be found here: https://github.com/PacktPublishing/D3.js-Quick-Start-Guide/tree/master/Chapter05.