NPM (Node Package Manager) is a package manager for JavaScript, primarily used to manage and share packages of code for Node.js projects. It allows developers to install, update, and manage dependencies within their applications, making it easier to reuse code and collaborate with others. NPM hosts an extensive repository of open-source packages that can be easily integrated into projects, ranging from small utility libraries to full-fledged frameworks. With its command-line interface, developers can quickly install packages, manage versioning, and publish their own modules for others to use.

NPM plays a crucial role in the Node.js ecosystem, streamlining the process of incorporating third-party libraries and tools into applications. By automating dependency management, NPM helps developers avoid conflicts and ensures that projects remain consistent and up-to-date. Additionally, NPM scripts can be used to automate various development tasks, such as running tests, building code, or deploying applications, further enhancing productivity and efficiency in the development workflow.