TL;DR — Linux I/O Models in 30 Seconds Linux supports five I/O models that determine how a process reads and writes data: blocking, non-blocking, I/O multiplexing (select, poll, epoll), signal-driven, and asynchronous I/O. Servers such as Nginx and Redis use epoll-based multiplexing; Node.js wraps the same under libuv. The models differ in who waits (process…