Node.js, or Node for short, is an open-source, cross-platform JavaScript runtime environment that allows executing JavaScript code outside of a web browser. Created by Ryan Dahl in 2009, Node.js is designed for building high-performance web servers and network applications. It utilizes the V8 JavaScript engine from Google Chrome, enabling it to run on various operating systems including Windows, Linux, Unix, and Mac OS X. Node.js features an event-driven and non-blocking I/O model, making it ideal for handling large concurrent connections, thus excelling in building real-time applications such as online gaming, chat applications, and real-time communication services. Moreover, Node.js adopts a modular architecture and leverages npm (Node package manager), enabling community members to share and reuse code, significantly fostering the growth and expansion of the Node.js ecosystem. Beyond server-side development, Node.js is increasingly used for building toolchains, desktop applications, IoT devices, and more. With its capabilities in handling file systems, database operations, and networking requests, developers can write full-stack applications in JavaScript, greatly enhancing development efficiency and convenience. In practice, many large enterprises and organizations have adopted Node.js as the development platform for their web applications, such as Netflix, PayPal, and Walmart, leveraging its performance improvements, streamlining development processes, and responding more rapidly to market demands.