Node.js Runtime Environment
Node.js is a back-end JavaScript runtime environment that allows developers to execute code on the server, outside the confines of a web browser. Built on Google's powerful V8 engine, it utilizes an event-driven, non-blocking I/O model, which makes it exceptionally lightweight and efficient for building fast, scalable network applications that handle numerous simultaneous connections. This architecture is ideal for creating web servers, APIs, and other data-intensive real-time services, enabling developers to use a single programming language (JavaScript) for both front-end and back-end development.