Concurrency vs. Parallelism

Concurrency vs. Parallelism

In this lesson — part of Concurrency Basics — you'll learn concurrency vs. parallelism in C++ and why it matters in real work.

Why it matters

Modern programs wait on networks and disks — async lets them stay responsive.

Key ideas

• Blocking vs. non-blocking
• Callbacks, promises, async/await
• Concurrency vs. parallelism
• Error handling in async code

In practice

Here's how it looks in idiomatic C++:

#include <future>
int slow_add(int a, int b) { return a + b; }
std::future<int> fut = std::async(std::launch::async, slow_add, 2, 3);
// ... do other work here ...
int result = fut.get(); // blocks until the value is ready -> 5

C++ note: std::async launches work and hands back a std::future; calling .get() is the await point that blocks until the result (or rethrows an exception from the task).

Try it yourself

Exercise: In C++, fetch two things concurrently and combine the results.

Recap

You now understand concurrency vs. parallelism and can apply it in C++. Mark this lesson complete and continue to the next one.