A brief introduction to Node.js for running JavaScript outside the browser.
Node.js is a server-side runtime environment built on Chrome's V8 JavaScript engine. It was created in 2009 by Ryan Dahl and it was a game-changer because it allowed developers to use JavaScript, a language traditionally confined to the browser, for backend development. This enabled the creation of full-stack applications using a single programming language. The core philosophy of Node.js is its non-blocking, event-driven architecture. This means that instead of waiting for a long-running task (like a database query or file operation) to complete, Node.js can continue to execute other code. When the task is finished, a callback function is triggered to handle the result. This model is highly efficient for I/O-heavy applications like web servers, APIs, and real-time services, as it can handle many concurrent connections with minimal overhead. Node.js comes with a rich ecosystem of built-in modules for tasks like file system access (`fs`), networking (`http`, `net`), and more. Furthermore, it is home to npm (Node Package Manager), the largest software registry in the world, which allows developers to easily install and manage third-party libraries to extend their application's functionality. This makes Node.js an incredibly powerful and popular choice for building scalable network applications.