The official website for Node.js describes it as an asynchronous event-driven JavaScript runtime. Node is designed to build scalable network applications. We will use it in this book to serve up our files and work with them in a browser. Node.js comes packaged with npm, a package manager for JavaScript, which will allow us to install packages globally and access them through the command line. In this section, we'll cover the installation process for each platform using the Node Version Manager (nvm).