That confirms my point that "concurrency" doesn't mean anything close to what the grandparent comment says, which claimed the concurrency is to do with overhead

That confirms my point that "concurrency" doesn't mean anything close to what the grandparent comment says, which claimed the concurrency is to do with overhead of parallelisation. What's more, it all mostly agrees with what I was saying. Look at this bit in particular: > This allows for parallel execution of the concurrent units Notice how it uses "parallel" to mean that the concurrent units (to use the quoted terminology) are actually executing at the same time, exactly as my previous comment says. OK, it avoided talking about "physical processors" or "cores", but that's what this boils down to on practical digital computers. Maybe the wording in my last comment wasn't 100% perfect, and there are some slight differences on details (e.g. the quoted Wikipedia text only seems concerned with processing-bound units of execution, not IO-bound waiting) but it's clearly talking about the same two definitions.