The shell, the shell… We all heard that. We know you can type some command in the shell in a Linux environment and get some output. But what does the shell actually mean?
“A shell is a program that runs commands”, says (Ward, 2014). That is basically it. You type some commands in, the shell executes them, then you get some output. Shell scripts, another popular term, are essentially just commands typed in a file called a shell script; so the shell has the same job – execute commands.
There are multiple kinds of shells. You can find more information here: (“5 Most Frequently Used Open Source Shells for Linux,” n.d.)
Before I end, it is important to note that programs like Terminal are not actually shells – they are graphical user interfaces running shell on your behalf. (Barrett, 2016) Figure 1 depicts this. This program with a graphical user interface, called a terminal emulator, interacts with the shell. (Shotts, 2019)