Learn how JavaScript really works under the hood with this complete breakdown of the event loop, call stack, microtasks, macrotasks, promises, setTimeout, and fetch API.
In this tutorial, we’ll use a simple JavaScript example and walk through it step by step to answer questions like:
👉 Why do some functions execute immediately?
👉 Why do promises always run before setTimeout?
👉 How does the event loop control execution order?
👉 What’s the difference between microtasks and macrotasks?
🧑💻 What You’ll Learn in This Video:
👉 How the JavaScript engine (V8) executes code
👉 The role of the call stack and heap
👉 How synchronous vs asynchronous code works
👉 The difference between Web APIs/libuv and JavaScript itself
👉 Real examples with setTimeout, Promise, and fetch
👉 A crystal-clear mental model of how tasks are scheduled
By the end of this video, you’ll fully understand JavaScript’s concurrency model — making it easier to debug tricky async issues and write cleaner, more efficient code.
On this page of the site you can watch the video online JavaScript Event Loop Explained | Call Stack, Microtasks & Macrotasks Made Easy with a duration of hours minute second in good quality, which was uploaded by the user Dennis Peter Munyao 12 September 2025, share the link with friends and acquaintances, this video has already been watched 121 times on youtube and it was liked by 11 viewers. Enjoy your viewing!