Cyberspace

Origin of the term
The term cyberspace, coined by science fiction author William Gibson in a short story “Burning Chrome,” and later user in his novel Neuromancer (1984), refers to the virtual world created within a computer and the network to which it is attached (also called a “computer-generated reality”). It includes the internal computer memory and wiring, and the networks to which the computer is connected. The prefix “cyber” is derived from the Greek word kybernan, which means to steer or control.

Online systems, for example, create a cyberspace within which people can communicate with one another (via e-mail), do research or simply window shop. Like physical space, cyberspace contains objects (files, e-mail messages, graphics, etc.) and different modes of transportation and delivery. Unlike real space, though exploring cyberspace does not require any physical movement other than pressing keys on a keyboard or moving a mouse.

Some programs, particularly virtual worlds, are designed to create a special form of cyberspace, one that resembles physical reality in some ways but defies it in others. Users are presented with visual, auditory, and even tactile feedback that makes cyberspace feel real.

U.S. Supreme Court
As stated by Supreme Court Justice Sandra Day O’Conner, in her concurring and dissenting opinion in Reno v. American Civil Liberties Union:

"Because it is no more than the interconnection of electronic pathways, cyberspace allows speakers and listeners to mask their identities. Cyberspace undeniably reflects some form of geography; chat rooms and Web sites, for example, exist at fixed “locations” on the Internet. Since users can transmit and receive messages on the Internet without revealing anything about their identities or ages . . ., however, it is not currently possible to exclude persons from accessing certain messages on the basis of their identity. Cyberspace differs from the physical world in another basic way: Cyberspace is malleable. Thus, it is possible to construct barriers in cyberspace and use them to screen for identity, making cyberspace more like the physical world and, consequently, more amenable to zoning laws. This transformation of cyberspace is already underway. * * * Internet speakers (users who post material on the Internet) have begun to zone cyberspace itself through the use of ‘gateway’ technology."

Presidential Directive
The National Security Presidential Directive 54/Homeland Security Presidential Directive 23 (NSPD-54/HSPD-23) defines cyberspace as

"the interdependent network of information technology infrastructures, and includes the Internet, telecommunications networks, computer systems, and embedded processors and controllers in critical industries. Common usage of the term also refers to the virtual environment of information and interactions between people."

Military
Cyberspace is

"[a] global domain within the information environment consisting of the interdependent network of information technology infrastructures, including the Internet, telecommunications networks, computer systems, and embedded processors and controllers."

"a domain characterized by the use of electronics and the electromagnetic spectrum to store, modify, and exchange data via networked systems and associated physical infrastructures."

The National Military Strategy for Cyberspace Operations identifies the following characteristics of cyberspace:


 * Created, maintained, owned and operated by public, private and government stakeholders and exists across the globe.
 * Changes as technology, architectures, processes, and expertise co-evolve to produce new capabilities and operating constructs.
 * Subject to the availability of the electromagnetic spectrum.
 * Allows high rates of operational maneuver that capitalizes on decision-quality information moving at speeds that approach the speed of light.
 * Enables operations across the domains of air, land, maritime, and space.
 * Transcends commonly defined organizational and geopolitical borders.
 * Formed by the interconnection of information and data transmission systems; supporting critical infrastructure; devices that store, process, and transmit data; and the use of software and hardware applications.
 * Includes data, voice, and video "at rest" and "in motion."
 * Readily accessible in varying degrees to other nations, organizations, partners, the private sector, and our adversaries.
 * Forms the foundation of the information environment.