Node.js is an open-source, cross-platform, back-end JavaScript runtime environment that runs on the V8 engine and executes JavaScript code outside a web browser. It enables developers to use JavaScript to write command line tools and server-side scripting, leading to the construction of web page content before the page is sent to the user's web browser. Consequently, Node.js represents a "JavaScript everywhere" paradigm, unifying web application development around a single programming language rather than different languages for server-side and client-side scripts.
