Non-blocking means threads never block. If the thread needs to block, the code is written in such a way that the thread gets notified at the right time and the process continues. Reactive programming lets you implement a non-blocking, declarative, and event-driven architecture.

One of the approaches to writing non-blocking applications is by using messages as the means of sending data. A thread sends the request and soon after that, the thread is being used for something else. When the response is ready, it is delivered back using another thread and the requesting party is notified so that further processing can continue:

The non-blocking concept is already implemented by well-known frameworks, such as Node.js and Akka. The approach that Node.js uses is a single thread that sends data in a multiplexing aspect.

In telecommunications and computer networks, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share an expensive resource. For more information about multiplexing, you can visit the following link: http://www.icym.edu.my/v13/about-us/our-news/general/722-multiplexing.html.