"Cyberpunk" is the term given to a particular genre of 20th-century science fiction. It is coined from two different words: "cybernetics"--the science of electronic, mechanical, and biological control systems--and "punk"--referring to modern street culture. The sense of the combined term is of ultratechnology grafted onto the culture of the street. The theory is that technology is changing so fast that each new discovery is old news before we had even had a chance to consider its implications.

The effect of that technology is a culture shock that not only separates one generation's ideals from the next generation's, but actually shakes the next generation's ideals as fast as they are formed. Mixing genetic material from animal to animal, or even from human to animal; raising crops of human embryos for organ transplants; creating machines that think like humans and humans that think like machines; all of these things, and more, are within our grasp. The problem is that they all tear at the definition of what it means to be human. And without that definition, we have no basis for human rights.

That is the realm of cyberpunk: the explore what it means to be human, or inhuman, in the world of the future.

--From 2300AD: Earth/Cybertech Sourcebook, by Games Designers Workshop