Parallelism & Concurrency

When multiple tasks are assigned on multiple cores on a system it is called parallelism

Let's look at some applications we use in our daily lives.

We can take Microsoft Word as an example, there are many tasks for Word to do at a time including spell check, UI update, grammar etc..

So these tasks should be performed without any delay or any distraction for the users

and what parallelism does is assign these tasks on multiple cores so that the users don't feel a lack of latency

Concurrency

Concurrency on the other hand talks about where tasks take their turns to get executed on a single core. It creates an illusion that the tasks are done parallelly but it is not.