Welcome to Professor Vegliante's Introduction to Linux
One shell to rule them all, one shell to find them, one shell to bring them all and in the same distro bind them. Command line is one of the many strengths of Linux based systems. ... A user has to un-learn and then re-learn the process of doing the same thing while they hop between distros.
Want to know what this means? This is the course for you.
Simply put, the shell is a program that takes your commands from the keyboard and gives them to the operating system to perform. In the old days, it was the only user interface available on a Unix computer. Nowadays, we have graphical user interfaces (GUIs) in addition to command line interfaces (CLIs) such as the shell.
On most Linux systems a program called bash (which stands for Bourne Again SHell, an enhanced version of the original Bourne shell program, sh, written by Steve Bourne) acts as the shell program. There are several additional shell programs available on a typical Linux system. These include: ksh, tcsh and zsh.