How Node.js handles a file request is much more efficient simply because it eliminates the waiting, and simply continues with the next request. It initially sends the task to the computer's file system. Afterward, it is ready to handle the next request. When the file system has opened and read the file, the server returns the content to the client. Running single-threaded, non-blocking, asynchronously programming, making it to be very memory efficient.
Another big difference is that in Node.js you control the environment. You know which version of Node.js you will run the application on unless you are building an open-source application that anyone can deploy anywhere. This is very convenient Compared to the browser environment, where you don't get the luxury to choose what browser your visitors will use.