A command-line interface (CLI) is a text-based way to control a computer or service by typing commands at a prompt rather than clicking through menus. It’s fast, precise and scriptable, making it ideal for automation, remote administration and working on servers or developer tools. Users enter commands with options (often called flags) and arguments, and the program returns plain text output that can be chained into other commands. CLIs run in a terminal on Windows, macOS and Linux, and while they have a steeper learning curve than a graphical user interface (GUI), they offer repeatability, low overhead and fine-grained control.
