Summary: in this tutorial, you will learn about what Node.js is and why and when you should use Node.js.
Introduction to Node.js
Node.js is an open-source cross-platform runtime environment that allows you to use JavaScript to develop server-side applications.
Every web browser has a JavaScript engine that compiles JavaScript code to machine code. For example, Firefox uses SpiderMonkey, and Google Chrome uses V8.
Because browsers use different JavaScript engines, sometimes, you will see that JavaScript behaves differently between the browsers.
In 2009, Ryan Dahl, the creator of Node.js, took the V8 engine and embedded it in an application that could execute JavaScript on the server.