Node.js is a runtime environment that enables us to run the JavaScript code outside of the browser, making it a very powerful and useful tool for developing various applications.

npm is a repository of Node.js packages and also a command-line utility for accessing and managing those packages. Using npm we can easily initiate a new Node.js project and import any desired project from the library of available projects.

To use Node.js:

• Install it from the official website(npm included);

• Open the command prompt and type in node --version to check if node is correctly installed (if Node's version is displayed, everything installed correctly);

There are some useful commands:

• Initiating a new node: npm init;
• Installing new packages: npm install <package name>;
• Running a node script: node <script name>.

With the help of Node we can set up a React project and test it conveniently using a package called create-react-app provided by Facebook, that includes all the required tools. We will explore more about it in a later section.