Initially, computer invention focused on complementing and replacing human functions. Computers required many components to imitate these functions.

X In order to replace human senses, computers needed input devices for perception and data entry.
X In order to be able to store data and process it like a human brain, computers needed processors and memory.
X In order to replace the human nervous system and be able to perform, computers needed software.
X In order to replace human hands, feet, etc., computers needed output devices.
X In order to be able to permanently store data and information, computers needed storage devices.
X In order to communicate with other computers, computers needed to be able to network and form an electronic community and electronic society.

Courtesy of Brooke Coggins's (tekGIANTS Office Manager) Professor. This is very thought provoking and I personally thought worth the read! Thank you!