The Shell works by working on an interface, either a
Command-Line Interface (CLI) or a Graphic User Interface (GUI) depending on the role, with a command syntax to complete the requests entered by the user and therefore improve or adapt its services.
The shell works because of its cognitive ergonomics and its purpose is to obtain the best workflow for the intended jobs, often allowing for some operations to be achieved much faster. It can be operated by a direct human-machine interface through the use of computer keyboard, pointing device or touchscreen.
All IT professionals will be familiar with this type of programming work and the commands to input to interact with the operating systems, from either their working, personal or educational work, with many being familiar with Shell-specific scripting language.