The event loop in Node.js is a mechanism that allows asynchronous code to be executed. It works by allowing the execution of code to be delayed until an event occurs, such as a user input, a network request, or a timer expiring. The event loop is responsible for queuing up tasks and scheduling them to be executed in the correct order.
For example, when a user makes an HTTP request, the event loop will queue up the request and wait for a response from the server. Once the response is received, the event loop will execute the callback function associated with the request. This allows the user to continue interacting with the application while the server is processing the request.