The Node.js website (https://nodejs.org/) describes it as a JavaScript runtime built on Chrome's V8 JavaScript engine. Node.js
uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. It can be used inside a desktop application (for example, it runs Microsoft Visual Studio code, built on the Electron open source project) and inside Internet Information Server or Azure, handling requests and responses, from an HTTP connection, inside an HTTP Server service, for web applications or API applications.
With Express.js
framework, Node.js can be considered as a competitor for Microsoft ASP.NET stack-based applications. They overlap in many ways but many considerations have to be made: