First of all, let me tell you something that may surprise you. Linux implements what is called "Everything is a file" philosophy. This means that on your Linux system, everything is represented by a file. For example, your hard disk is represented by a file. A running program (process) is represented by a file. Even your peripheral devices, such as your keyboard, mouse, and printer, are all represented by files.
With that being said, an immediate consequence of "Everything is a file" philosophy is that Linux administrators spend a substantial amount of their time editing and viewing files. And so you will often see Linux administrators very proficient at using text editors. And this chapter is dedicated to just that. I want you to be very comfortable using various text editors in Linux.
There are a lot, and I mean a whole lot, of text editors...