In this section, you'll learn how to run Linux command-line programs and what the basic structure of the command line is. You will also learn what program options and arguments are and why they are important for customizing your commands.
When we say the Linux command line, what we really mean is the shell. It's important to know that the shell is not the same as a terminal emulator. A Terminal is a screen or window that lets you access a Linux server's input and output. A shell is just a program that runs on the server as does any other command and which awaits, interprets, processes, executes, and responds to commands typed in by the user.
First, open up a new terminal emulator and log in to your CentOS 7 server ...