Synchronous vs Asynchronous vs Concurrent vs Parallel

What is the difference and why does it matter?

Photo by Edurne Chopeitia on Unsplash

We developers like to throw around terms that feel natural to us, but are technical terms that most non-developers don’t use in the same way. This article is aimed at all the poor souls who have to deal with us, e.g. product managers, product owners, scrum masters, business people.