hardware//I/O

I/O (input/output) is the set of mechanisms through which a CPU communicates with the external world: storage, network, sensors and displays. Its latency often dominates real-world performance far more than raw compute speed.

I/O (input/output) is the set of mechanisms through which a CPU communicates with the external world: storage, network, sensors and displays. Its latency often dominates real-world performance far more than raw compute speed.

Software triggers I/O through a syscall (the boundary between user and kernel), and hardware uses MMIO (memory-mapped registers) or DMA (direct memory access that bypasses the CPU).