In the context of Node.js, a package manager is a tool that allows developers to easily install, manage, and share reusable code packages (also known as modules or libraries) written in JavaScript.

Node.js has two popular package managers: npm (Node Package Manager) and Yarn. npm is the default package manager for Node.js, while Yarn is a newer alternative that offers some additional features such as offline installation and deterministic dependency resolution.

Both npm and Yarn provide a command-line interface (CLI) that developers can use to search for and install packages from a centralized registry, as well as tools for managing and publishing their own packages. They also maintain a dependency tree for each project, which helps ensure that all required packages are installed and compatible with each other.

Overall, package managers in Node.js help simplify the process of managing dependencies and enable developers to build applications more efficiently by leveraging existing code and functionality