How libuv Powers Node.js Asynchronous and Non-Blocking I/O

libuv is an open-source C library that serves as a core component of Node.js, enabling asynchronous, non-blocking input/output operations. Since JavaScript itself lacks native ability to handle file reads, network sockets, or timers, Node.js delegates these tasks to libuv, which communicates directly with the operating system. libuv implements the Node.js Event Loop, which continuously monitors completed async operations and queues their callbacks for JavaScript execution. Behind the scenes, libuv maintains a thread pool of four worker threads by default, handling file system operations without blocking the main JavaScript thread. It also manages networking, timers such as setTimeout and setInterval, and is the primary reason Node.js can efficiently serve thousands of simultaneous connections.