Window Managers and the Command Line:
Window Managers (WM)
Most users will use Linux like they use Windows, ie. With a GUI (graphics user interface). So you will see a Desktop and Icons.
MS Windows only has one Desktop and one Window Manager.
Linux has several desktops (2 to 4 normally) and a choice of Window Management (WM).
The most popular WM is KDE since it looks a lot like MS Windows (Mint,Mageia and SUSE use this almost exclusively). The next most popular WM is GNOME (used by Ubuntu, Fedora Core). There are still less WM XFCE and Enlightenment to name a few others.
KDE and GNOME are very large WM taking up a lot of space on the hard drive. So if space is limited on your computer, you might pick a distro with a smaller WM.
Most people will undoubtedly use KDE or GNOME.
Some distros give you the ability to run several different Window Managers so you can try them out.
Most users of Linux will not even be aware of which gui they are running. Whatever loads up is what they use.
CLI (command line interface)
You may never use this but as you become more adept with Linux, it is a very powerful tool.
Just as Windows had the DOS shell built in, so too has Linux. In fact most Linux distros have two or more DOS-like shells, BASH and SH or TSH to name the most popular.
As you may or may not know, the DOS (Disk Operating System) shell has commands that can access any part of the machine. They are powerful commands and need to be studied before using.
In Linux the ‘DOS’ or CLI mode is used when you open a Terminal or Console program.
Basically, when you enter a terminal you have to know some of the underlining Linux ‘shell’ commands. These commands are found in the /bin and /sbin folders. However, some of them are MS DOS-like.
For example, cd means the same thing in DOS – change directory. ls means, List the folder, and co for copy a file. However, there are some new ones that you will have to learn, if you venture into the Terminal part of Linux.
The most often used command is the ‘man’ command. It is used in conjunction with another word to DISPLAY the MANual pages for various parts of Linux. ‘man grub’ for example will display information about the important program ‘grub’ which sets up the start menu to Linux or Windows.
To make matters more complex, there is more than one shell available in most Linux distros. Almost all of the distros use the BASH shell. However, most people will not need to get into another shell.
Just remember, if all you see is text or a flashing cursor, you are in terminal mode. Type ‘exit’ to get out of it or simply close the window.
The most used mode of Linux is the GUI or ‘x-window' mode. This is what MS Windows use.
In Linux this is called the x11-system. When you are operating in a Linux GUI or graphics mode then this is where you’re at.
The Window Manager systems of Linux can emulate the exact same clicks and key-strokes as MS Windows. In fact, you can change the ‘look and feel’ of the system to suit your needs and desires. There is even a way to make the Window Manager emulate the MacIntosh OS. So Linux will make you feel right AT HOME when you use your mouse.
The one nice thing in Linux is that it is easy to run Multiple desktops and run processes at the same time.