As everyone knows, the three main components that make up a computer are the CPU, memory, and I/O (data input/output). There's no need to elaborate on the CPU and memory, but what exactly is I/O? I/O is short for IN and OUT. Simply put, the CPU needs to extract data from the memory for computation, then return it to the memory after the computation is complete, or directly send electrical signals to certain pins to operate external devices. For the CPU, extracting data from memory is called IN. After computation, sending the data directly to some other pins or returning it to memory is called OUT. In terms of disk operations, IN refers to the process of writing data to the disk, while OUT refers to reading data from the disk.
I/O is just a process, so why do we study it? Because we must understand the flow and processing of data within a computer system. Data undergoes continuous I/O processes in each component, being passed to the CPU for computational processing, and then going through another I/O process to ultimately reach output devices for human use.
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