https://readosapien.com/queues-in-node-js/- queues in node js

io.js

const fs = require('fs'),
   path = require('path'),
   filePath = path.join(__dirname, 'test.js');

setTimeout(()=> console.log("setTimeout"), 0);
Promise.resolve().then(() => console.log("promise"))

fs.readFile('filePath', function() {
   console.log('readFile');
});