You're blending concepts. All parallelism is asynchronous, but not all "asynchrony" is parallel. I have to use Python as as an example since I don't have much

You're blending concepts. All parallelism is asynchronous, but not all "asynchrony" is parallel. I have to use Python as as an example since I don't have much experience with JavaScript, but when you're using asyncio, that's single threaded non-blocking IO (asynchronous). Each use of "await" yields execution back to the event loop, and it can can schedule some other task to run. Tasks can run asynchronously, but no in parallel. When you use the multiprocess library you are actually creating new threads that run in parallel (I'm ignoring the threading library because it just muddies the water). That's also asynchronous execution. I don't know the semantics as well in JavaScript, but I'm sure the principle is the same. At certain points you can yield to the runtime and it will schedule other pending tasks to execute while the current one is pending. My point was that mistake I see people make (in Python) is they think of their program in blocking terms by default. So they get this frustrating coloring problem because they are trying to shoehorn in non-blocking calls. If instead you design the application from the start with asyncio in mind, it makes things much simpler.