Asynchronous JavaScript

JavaScript is a single threaded programming language, which means for the most part it will be run as a single process in your computer (essentially writing and running it top to bottom).

To be an effective web developer you have to be comfortable writing async code when the situation calls for it. For those times JavaScript does have a few async tricks up its sleeve. One of the most common is setTimeout() which allows you to break out of the inherent JS behavior of executing code line by line starting at the top. Let’s explore these ideas more in a video: