Command line (terminal)

A text interface for running programs with commands; a terminal hosts the session, while a shell interprets many of the commands you type.

A command usually names a program followed by options and arguments. The program can print output, change files, start a server, or contact an external service. Terminals can run locally, over a remote connection, inside an editor, or through an agent. Because commands can have destructive effects, the text itself and the current directory matter.

Builder example

Build, version-control, deployment, and diagnostic tools commonly expose command-line interfaces. An exit code and output provide evidence about what the program reported, but success may still need a runtime or external-state check.

Common confusion: The terminal is the window; the command line is the prompt inside it where you type, and the shell is the program that reads and runs what you type. People use the three words loosely, but they name the container, the input, and the interpreter.