I think the problem is getting terms mixed up. A client-server arrangement on multiple machines can run in single threads and not share memory and is still con

I think the problem is getting terms mixed up. A client-server arrangement on multiple machines can run in single threads and not share memory and is still concurrent. And concurrent code can still be run on a single processor. The ability to stretch an application across more than one machine is obviously essential to the modern world. The internet is by definition a kind of distributed computing system. Some languages have features that promote a particular kind of parallel programming. But they are not suited to every task and thats ok!