What is cshell?

Csh (C shell) is a Unix shell created by Bill Joy while a graduate student at the University of California, Berkeley, in the late 1970s. It is a command interpreter that is used as a user interface to the operating system. Csh's syntax and features, such as command history and aliases, were influential and widely adopted, especially in interactive use. Although still available on many Unix-like systems, it is generally considered less suitable for scripting than other shells like Bash or Ksh due to some quirks and inconsistencies in its syntax.