The I/O allows the computer to obtain information from the outside world, and send the results of its work back there. There is an broad range of I/O devices, from the familiar keyboards, monitors and floppy disk drives, to the more unusual such as webcams.
What all input devices have in common is that they encode (convert) information of some type into data which can further be processed by the digital computer system. Output devices on the other hand, decode the data into information which can be understood by the computer user. In this sense, a digital computer system is an example of a data processing system.
