I/O multiplexing refers to the concept of processing multiple input/output events from a single event loop, with system calls like poll and select (Unix). –WikipediaIntroductionkqueue(on MacOS) and epoll(on Linux) are kernel system calls for scalable I/O event notification mechanisms in an efficient manner. In simple words, you subscribe to certain kernel events and you get notified when any of those events occur. These system calls are desigend for scalable situations such as a webserver where ...