Node.js is a backend technology used for the development of scalable and high-performance web applications. Since it employs JavaScript on the server side, you can easily achieve two-way communication between the front-end and back-end. With Node.js, your site can provide a fluid browsing experience by processing multiple user requests at once without any lag.
Node.js facilitates real-time capabilities like chat or live updates, which are key to increasing user engagement in a website. Additionally, its faster development and testing cycles make building a website quicker.