A parallel program, on the other hand, is one that merely runs on multiple processors, with the goal of hopefully running faster than it would on a single CPU.
It's an incredibly vague definition that actually encompasses concurrency too..
Wikipedia puts it quite succinctly:
Parallel computing is a form of computation in which many calculations are carried out simultaneously,[1] operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently ("in parallel").
The WP article then goes on to discuss specific forms of parallelism; some concurrent, some not necessarily so.
This article appears to be so heavily focused on the idea that concurrency and parallelism are discrete and disconnected that it seems to forget there is a bigger picture.
The writer has a strong key point. Parallelism !== Concurrency (note the double =). However it's ignoring the fact that they DO intersect frequently.
