Understanding parallel programming

Parallel programming, as the name suggests, is just a program running in such a way that instances of that program are running simultaneously multiple times.

Concurrent programming, on the other hand, is very similar to parallel programming, but with the difference that tasks never happen together.

Parallel versus concurrent programming

To understand the difference between parallel and concurrent programming, let us consider an example.

Suppose there's a competition to eat candies put on two plates. Plates are at a distance of five meters from each other. Let's say you're the only player for now, and the constraint is that you have to keep the number of differences in candies on both plates to less than two.

What will you do here? You have to eat from plate one, run five meters to plate two, eat from plate two, run five meters again to plate one, and so on.

Now, let's assume you have got a friend. Now, both of you can choose a plate and start eating your own...