What is the exact difference between a 'terminal', a 'shell', a 'tty' and a 'console'?

[kingjane]

In unix terminology, the short answer is that:
terminal = tty = text input/output environment
console = physical terminal
shell = command line interpreter
https://unix.stackexchange.com/questions/4126/what-is-the-exact-difference-between-a-terminal-a-shell-a-tty-and-a-con