I don't see how compute a() in parallel with b() and handle mouse events concurrently (could be a()) with keyboard events (could be b()) differ and how does

I don't see how compute a() in parallel with b() and handle mouse events concurrently (could be a()) with keyboard events (could be b()) differ and how does compute a(0), a(1), ..., a(N) in parallel differ from handle events from 1000 sockets concurrently which would be something like a(event0) a(event1)? Don't we require the same tools for "task parallel" and "task concurrent" as well as "data parallel" and "data concurrent"? To me they don't seem orthogonal but I believe they are very much the same thing.