Angular CLI is an 𝗖ommand 𝗟ine 𝗜nterface which is part of Angular eco-system.
Angular CLI purpose is to speed up the coding experience with friendly commands:
Starts a new Angular project by laying down the complete architecture of the project.
Generates the basics files required for a component, directive, service, class, etc.
Launches the automated tests of your project.
Compiles and optimizes your whole project to prepare a delivery on production.