Shell DEVELOPMENT
The shell is the layer of programming that understands and executes the commands a user enters. In some systems, the shell is called a command interpreter. A shell usually implies an interface with a command syntax (think of the DOS operating system and its "C:>" prompts and user commands such as "dir" and "edit"). A shell is a software interface that's often a command line interface that enables the user to interact with the computer. Some examples of shells are MS-DOS Shell (command.com), csh, ksh, PowerShell, sh, and tcsh.
