[davidron]

So long as one executor is executing the recipe/procedure/etc it makes sense to simplify directions to make them appear synchronous. When I turn my computer on and wait for it to start, I don't literally freeze up and stop breathing. I go do other things and wait for a signal that startup is complete or I poll the status of the computer from time to time. The synchronous instruction "wait for the computer to start up" is interpreted as "do whatever you want or need to do until the computer has started up".

As soon as two parties are involved, instructions start making sense asynchronously. Try writing a recipe for baking a cake by two bakers, keeping both chefs occupied the entire time. You'll see that the instructions must be read asynchronously otherwise each baker would not be able to continue reading his/her instructions when a "thread" of operation for the other baker has been called out.

[jbrat]

Async is not parallell. With Node, only one of your bakers would actually be working at a time since Javascript does not support multithreading! Only way to achieve this would be dispatching to other node processes and start handling this yourself. With the JVM however you could actually do things in parallell without any such RPC handling.