Chapter 1, Introduction to Linux, introduces you to the general idea of Linux. Topics range from virtualization, and the installation of VirtualBox and CentOS, through to the working dynamics of VirtualBox, and SSH connectivity with VirtualBox.
Chapter 2, The Linux Command Line, sheds some light on a wide range of topics, including shell globbing, an introduction to command-line operations, the navigation of files and folders in the Linux filesystem, the central idea of different streams, regular expressions, and important commands such as grep, sed, and awk.
Chapter 3, The Linux Filesystem, focuses on the working dynamics of the system, including file links, users and groups, file permissions, text files, text editor, and an understanding of the Linux filesystem.
Chapter 4, Working with the Command Line, walks you through essential Linux commands, signals, additional programs, processes, and Bash shell scripting.
Chapter 5, More Advanced Command Lines and Concepts, provides an overview of basic networking concepts, services, ACL, troubleshooting, setuid, setgid, and sticky bit.