Terminal

Terminal/Console

Execution environment for applications. Provided by the kernel. Usually provides the hardware (keyboard).

Exposes text buffer. Only one application runs in foreground (this application "owns" keyboard/mouse).

Shell

Application. The command interpreter.

Uses terminal, exposes OS functionality for user (via commands). Allows configuration of execution environment (via variables)

Environment variables

Shell utilizes two types of variables:

• local: accessible only via current shell. Not passed to child processes. Created: a=some_value.
  Displayed with set command
• exported: passed to every child process. Created: export a=some_value.
  Displayed with env command

References

1. https://unix.stackexchange.com/questions/4126/what-is-the-exact-difference-between-a-terminal-a-shell-a-tty-and-a-con
2. http://mywiki.wooledge.org/SignalTrap