Shell (computing)

In computing, a shell is a user interface for access to an operating system's services. In general, operating system shells use either a command-line interface (CLI) or graphical user interface (GUI), depending on a computer's role and particular operation. It is named a shell because it is the outermost layer around the operating system kernel. In computing, a shell is a user interface for access to an operating system's services. In general, operating system shells use either a command-line interface (CLI) or graphical user interface (GUI), depending on a computer's role and particular operation. It is named a shell because it is the outermost layer around the operating system kernel. CLI shells require the user to be familiar with commands and their calling syntax, and to understand concepts about the shell-specific scripting language (for example bash script). They are also more easily operated via refreshable braille display, and provide certain advantages to screen readers.