Node.js is a JavaScript runtime environment that allows you to execute JavaScript code outside of a browser. It is an open-source, cross-platform environment that can be used to create server-side applications. Node.js is a powerful tool for creating fast and scalable network applications.
Express.js is a web application framework for Node.js. It is designed for building web applications and APIs. Express.js provides a robust set of features for web and mobile applications, such as routing, middleware, view system, etc.
Example:
If you want to create an application that displays data from a database, you can use Node.js to connect to the database and retrieve the data. Then, you can use Express.js to create the routes and views to display the data.