To set up Node.js on your machine, you will need to visit the official download page at https://nodejs.org/en/download and follow the instructions for your operating system.
If you are an OS X or Linux user, you can additionally install the node version manager (nvm) following the instructions at https://github.com/creationix/nvm. This tool allows us to install multiple versions of Node.js on the same machine and to switch between them in a matter of seconds. If you are a Windows user, you will need to install https://github.com/coreybutler/nvm-windows instead.
If we want to use one of the Node.js core API modules, all we need to do is to import it. We don't need to install an additional npm module. For example, the filesystem module can be used to read and write files and manage directories. If we want to use the filesystem API, all we need to do is to...