Arduino CLI is an all-in-one solution that provides Boards/Library Managers, sketch builder, board detection, uploader, and many other tools needed to use any Arduino compatible board and platform from command line or machine interfaces.
In addition to being a standalone tool, Arduino CLI is the heart of all official Arduino development software (Arduino IDE, Arduino Web Editor). Parts of this documentation apply to those tools as well.
You have several options to install the latest version of the Arduino CLI on your system, see the installation page.
Follow the Getting started guide to see how to use the most common CLI commands available.