In computer programming, a thread pool is a software design pattern for achieving concurrency of execution in a computer program. Often also called a replicated workers or worker-crew model, a thread pool maintains multiple threads waiting for tasks to be allocated for concurrent execution by the supervising program. By maintaining a pool of threads, the model increases performance and avoids latency in execution due to frequent creation and destruction of threads for short-lived tasks. I want to get a better grasp of the pattern so I made a dummy running example, with a few alternations. I also added a visual representation using a HTML basic client & websockets. The user can send fake jobs to process, and everything is slowed down (to seconds) so the user can observe the worker behaviours.