I/O or, alternatively known as input/output refers to any operation, device or program that creates linking or communication between a computer system and outer objects. Input means to enter data to the system, and output is the sent data from the system. Basically, data transferred from or to the host and from or to a secondary device is termed as I/O. In doing so, several input and output devices are used. For example, mouse, keyboard, CD/DVD drives, punch card, etc., are input devices that enter the data to the system. Alternatively, display monitor, printers, etc. are the output devices. Alternatively, DVD-R/W acts as both an input and output device accordingly.
In order to accomplish the desired communication, an I/O interface s required. And to do so, the interface should have the required logic that is capable of interpreting the device location engendered by the main processor. HP, Sun Microsystems, Dell, Compaq is some of the renowned brands that provide such I/O boards
