The term cyberspace was originally coined by science fiction author William Gibson in the short story Burning Chrome and exposed to a wider audience with the novel Neuromancer (which later became the game Neuromancer).
"Cyberspace. A consensual hallucination experienced daily by billions of legitimate operators, in every nation, by children being taught mathematical concepts... A graphic representation of data abstracted from banks of every computer in the human system. Unthinkable complexity. Lines of light ranged in the nonspace of the mind, clusters and constellations of data. Like city lights, receding."