NPM (Node Package Manager) comes bundled with Node.js and manages the JavaScript libraries your block projects depend on. It replaces the old practice of manually copying code into your project.
Packages are reusable sets of code that solve specific problems. WordPress itself uses dependencies like PHP Mailer, and the block editor relies heavily on JavaScript packages for functionality like hooks, data management, and UI components.
NPM handles version management, security updates, and dependency conflicts automatically. You install packages with simple commands, import the functions you need, and the build process bundles everything together for production.