[Csapp] Concurrency and parallelism

It's been a long time learning computer, and the concept of concurrency and parallelism has not been thoroughly understood. After the examination, thought oneself understand, however until looked at the Csapp only really understand these two concepts.

concurrency (concurrency)

Flow x and stream y concurrent runs mean that the flow x starts before the end of the flow y, or the stream y starts before the end of the flow x begins.

, process A is concurrent with process B, process A is concurrent with process C, and process B is not concurrent with process C.

Parallel (parallel)

Parallelism is a true subset of concurrency.
Concurrency may occur on a single processor or on a multiprocessor. Flow A and stream B are parallel, then stream A and stream B run concurrently on different processors.

From for notes (Wiz)

[Csapp] Concurrency and parallelism