This presentation discusses the major functions of input/output (I/O) modules. An I/O module connects peripheral devices like keyboards and printers to a computer system, interfacing both with the system bus and tailored data links. The main functions of an I/O module are to provide control and timing for data transfer, facilitate communication between the processor and connected devices, buffer input and output data, and detect errors. I/O devices are necessary for a computer system to allow interaction and data transfer with external hardware used by humans and other systems.