What is Node.js https://nodejs.org/en/?
Node.js is a JavaScript runtime built on the V8 engine by Google. V8 engine is written in C++ and it compiles JavaScript code to machine code and adds other features like accessing the file system, etc. JavaScript can be run anywhere using Node.js not just on the browser. We can use Node.js to run a server, handle business logic and return responses. Node.js is event driven. Single threaded at application level
https://nodejs.org/en/docs/guides/event-loop-timers-and-nexttick/
Event loop --> Keeps on running as there are event listeners registered