What is a shell? How does it work with the kernel? With the user?

What will be an ideal response?

A shell is a command interpreter; it starts the program you call from a com-
mand line and passes your instructions (arguments) to the program. The

shell is also a programming language; it can run files of commands, similar
to DOS batch files, when you issue a single command to the shell.
When you use a shell in interactive mode (from a command line), the kernel
accepts input from your terminal (by default) and passes it to the shell. It
also takes output from the shell and displays it on the screen (by default).
The shell accepts a command from a user, starts execution of the program
named in a command, and passes the command line to the program.