Metaverse is the current term for what was previously known as cyberspace. Our current multitude of "metaverses" is kind of like the early days of the internet when it was compartmentalized into CompuServe, America Online, etc. When all these compartments converge, then we will be closer to achieving a metaverse. Some other great works that portray this cyberspace are the books of William Gibson such as Neuromancer (1984), and Tad Williams' Otherland series (1996)