Many of the chapters in this book introduce a topic, and then go deeper, because the related exam requires that deeper knowledge. Unlike most other chapters in this book, this chapter introduces each topic briefly, and then moves on to the next topic. The point of this chapter is to introduce you to the general ideas behind a handful of other WAN protocols.
Just to give the technologies some context, this chapter breaks down the technologies into two major sections. The first looks at WAN technologies used to create private WAN services, usually for businesses. The second section looks at WAN technologies used to access the Internet, whether for businesses or consumers.