This chapter provided a general introduction to the D3.js library, describing its architecture, modules, and showing how to set up a small D3 application that, although very simple, demonstrated one of the central paradigms in D3, which is driving the appearance of a visualization using arbitrary data.
The next chapter will consist of reference topics that cover fundamental technologies used by D3, such as SVG (an introductory tutorial), JavaScript (mostly a review of the fundamental data structures in ES 2015), and Canvas (a short reference). There is also a short section on data formats. If you are comfortable with all these topics, or if you want to start using D3 right away, you can skip them now and proceed to straight Chapter 3, Quick Start.