The name shell results from the name shells (on the beach) and means an outer layer of interface between the user and the kernel of the operating system.
A shell is a piece of software that provides an interface for users to an operating system.
Operating system shells are divided into two categories : command-line shells and graphical shells.
- Command-line shells provide a Command-Line Interface, in short : CLI to the operating system.
- Graphical shells provide a Graphical User Interface, in short : GUI.
The primary purpose of the shell is to invoke or launch another program. They have also additionnal capabilities such as viewing the contents of directories.
