event loop

https://amplication.com/blog/nodejs-development-all-you-need-to-know
https://blog.risingstack.com/node-js-at-scale-understanding-node-js-event-loop/
https://blog.logrocket.com/complete-guide-node-js-event-loop/

Event loop
Js is single threaded language so it can only execute one thing at a time.
Although Node.js is single-threaded, it uses an event-driven, non-blocking I/O model to handle multiple requests simultaneously without blocking others. This behavior is achieved through the event loop. event loop is a continuously running, semi-infinite loop which runs until the nodejs application is running


parts of event loop

Call Stack: The call stack keeps track of all the functions that are currently being executed. When a function is called, it's added to the top of the call stack, and when it returns, it's removed from the stack.