Node.js
Node.js is an open-source, cross-platform JavaScript runtime environment that allows developers to execute JavaScript code outside of a web browser, primarily on the server-side. It uses the V8 JavaScript engine from Google Chrome and provides an event-driven, non-blocking I/O model, making it efficient for building scalable network applications. It includes a built-in package manager (npm) and a rich ecosystem of libraries and frameworks.
Developers should learn Node.js for building fast, scalable server-side applications, particularly real-time applications like chat apps, APIs, and microservices due to its non-blocking architecture. It's ideal for full-stack JavaScript development, allowing code reuse between frontend and backend, and is widely used in modern web development, IoT, and DevOps tooling. Use cases include web servers, RESTful APIs, data streaming applications, and command-line tools.