Javascript – check out the Event Loop

You can read more on the Event Loop here, this is quite low level subject matter, and most developers may have never even heard the Event Loop, let alone understand the dynamics involved. If you are one of those developers, don’t worry, this isn’t anything to be ashamed of, after all many of the dynamics of the event loop are abstracted away by design, as most web developers need, nor should ever concern themselves with it.

But to conclude, I do think there is merit to reading up on it and having at least a little understanding, for example, how JS manages concurrency, or setTimeouts work.