What Is Cyberspace?
A good definition of Cyberspace can be found at Wikipedia, a synopsis would be: While cyberspace should not be confused with the internet, the term is often used to refer to objects and identities that exist largely within the communication network itself, so that a website, for example, might be metaphorically said to "exist in cyberspace."
According to this interpretation, events taking place on the internet are not happening in the locations where participants or servers are physically located, but "in cyberspace". Now ubiquitous, the term has become a conventional means to describe anything associated with computers, information technology, the internet and the diverse internet culture. Cyberspace is recognized as part of the US National Critical Infrastructure.
What Is Cyberspace-University of Michigan
There are several definitions, many are similar to the University of Michigan we get, "A term coined by William Gibson, a science fiction writer, to refer to a near-future computer network where users mentally travel through matrices of data. The term is now used to describe the Internet and the other computer networks."
What Is Cyberspace-Princeton
From Princeton we get much the same cyberspace (a computer network consisting of a worldwide network of computer networks that use the TCP/IP network protocols to facilitate data transmission and exchange).
What Is Cyberspace-U.S.Government
The U.S. government under the Bush administation had this to say in their "Secure Cyberspace" directive, "The way business is transacted, government operates, and national defense is conducted have changed. These activities now rely on an interdependent network of information technology infrastructures called cyberspace."
You can get a complete copy here for free Cyberspace. That should give you a well rounded definition of cyberspace. The image is from Flickr and it's called "this is what cyberspace looks like"
Any comments are always welcome.