Comment by Salgat

Parallel programming is simply a type of concurrent programming. Concurrent means that two tasks can both progress in a given duration. On a single core computer every thread runs concurrently. Parallel expands on concurrency to mean that two concurrent tasks can also run at the exact same time. On a multi-core computer threads can run in parallel. In many cases concurrent programming and parallel programming have little to no difference, and you program with the assumption that every task can run in parallel (for example, whenever you use async/await or the threadpool).