Shell is a UNIX term for the interactive user interface with an operating system. 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").
By submitting your personal information, you agree that TechTarget and its partners may contact you regarding relevant content, products and special offers.
As the outer layer of an operating system, a shell can be contrasted with the kernel, the operating system's inmost layer or core of services.