A Unix shell is a command-line interpreter or shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting language, and is used by the operating system to control the execution of the system using shell scripts.
“A shell script is a computer program designed to be run by the Unix shell, a command-line interpreter. The various dialects of shell scripts are considered to bescripting languages. Typical operations performed by shell scripts include file manipulation, program execution, and printing text.”
Following are the different types of Unix shells: B shell – /bin/sh – This is the default Unix shell for many Unix operating systems . … tcsh is the default shell of FreeBSD and its descendants. Essentially it is C shell with programmable command line completion, command-line editing