What is a Linux Shell ?
A Linux or Unix Shell is your command line interface to the Linux Operating System.
If takes input from the user, interprets the input and executes it onto the OS and displays the results on the screen or performs some other action, depending on the input shell command
Shells have many built-in features such as environment variables, aliases, command completion, functions for programming and shell command help.
There are several ways to get to a shell interface in Linux. Three of the most common are the shell prompt, Terminal window, and virtual terminal
In most Linux systems, your default shell is the bash shell. To and out what your default l
shell type the following command:
$ echo $SHELL
/bin/bash
Other common Linux Shells include csh, tcsh, sh, ksh