Node.js is a server-side javascript framework built on Chrome's V8 Javascript engine, which can be used to create web servers and to build applications that can be run on the server. It is an open-source, cross-platform framework.  Node.js provides a runtime environment for executing JavaScript code outside of a browser. It has an event-driven architecture, so it is not necessary to implement long polling or keep-alive connections in order to achieve scalability and high availability with Node.js apps. The runtime environment of Node.js provides some core libraries that are used by most applications, such as HTTP, HTTPS, file system, Zlib and crypto libraries
It was originally released in 2009 by Ryan Dahl as a way to simplify the process of developing scalable network applications and has become one of the most popular web application frameworks in use today. It has been gaining popularity in recent years due to its scalability and performance. With Node, developers can create high-performance web servers using JavaScript which is a language that most developers are familiar with and it has a huge community of users and contributors which makes it easier for new developers to learn the framework and get help when they need it