The definition of concurrency can be described as follows:

As the definition says, concurrency is all about breaking the entire task into small parts and then executing them concurrently (there's a small difference between concurrent execution and parallel execution, which we will discuss shortly).

So, what does it mean to execute subcomputations concurrently? Let's look at a real-life example. Think of a situation where you're cooking a new dish at your home and you have three chores—bring the spices, cut the vegetables, and also marinate something. Now, if you're doing it all alone, you have to do them one by one, but if you have a family member at your disposal, then you can distribute the tasks between the two of you. You can cut the vegetables while the other person is bringing the spices, and whoever between you two completes early can continue on the third task—marinating the food.

You can think of you and the family member (who helped you) as two threads, or, to be more specific, you're the main thread of the program (here, cooking) as you're the responsible person for the entire job, and you'll be distributing tasks between you and the family member, who is a worker thread. Together, you and your family member form a thread pool.

The entire program will execute faster if there are more threads and the complete task is divided properly among them.