Cyberspace connects computers across the globe although it does not physically exist anywhere. Essentially cyberspace is a domain consisting of electric and magnetic fields to store and exchange data through interlinked systems and supporting physical infrastructures like computer networks and servers. Cyberspace is not dependent on any material medium and can exist in vacuum.
Cyberspace is not synonymous with internet or the World Wide Web.
The internet is a collection of interconnected computer networks linked by wireless connections, fiber optic cables etc.
The web is a collection of interconnected resources and documents linked by hyperlinks and URLs. The World Wide Web is one of the services available via the internet.
However, such resources and documents including websites can be said exist metaphorically on the cyberspace.
The notion of cyberspace is not the resource content available to the web visitor but rather his opportunity of browsing among different websites with always chances of coming across something new, unknown or unexpected; facilitated by connecting loops between such visitor and the rest of the system.