What is the difference between concurrency and parallelism?

Question

What is the difference between concurrency and parallelism?

Examples are appreciated.

Answer 1

Great, let me take an scenario to show what I understand. suppose there're 3 kids named: A, B, C. A and B talk, C listen. For A and B, they are parallel: A: I am A. B: I am B.

But for C, his brain must take the concurrent process to listen A and B, it maybe: I am I A am B.