What is the event-driven programming paradigm in Node.js and how does it make Node.js more efficient?

Event-driven programming is a key feature of Node.js that allows developers to write asynchronous code using event listeners and callbacks. In this paradigm, Node.js utilizes an event loop to handle multiple concurrent operations without blocking the main thread. When an event occurs, such as a user input or a file read operation, Node.js triggers the corresponding event handler, which is executed asynchronously.

This event-driven architecture makes Node.js more efficient because it enables non-blocking I/O operations. Instead of waiting for each operation to complete before moving on to the next one, Node.js can efficiently handle multiple tasks simultaneously. This results in better performance and scalability for applications built with Node.js, especially when dealing with high loads or a large number of connections.