What is CLI?
A tool you control by typing text commands in a terminal, with no graphical interface.
// Explanation
CLI (Command Line Interface) is any program you use from a terminal by typing commands — no buttons, no windows. Most developer tools are CLIs: Git, Docker, npm, the AWS CLI, Vercel CLI, etc. They're faster to use than a visual interface once you know them, and they can be easily chained and automated in scripts. The opposite is a GUI (Graphical User Interface) — what most people use day to day.
// Example
Instead of opening the GitHub app and clicking 'Commit', you type `git commit -m 'message'` in the terminal. That's using Git's CLI.