The “city” in City of Bits is that created by online “architecture.” Author William J. Mitchell, then a professor at the Massachusetts Institute of Technology, explored the multiple ways that spatial and location analogies had been used (as of the 1990s, when he wrote the book) for online phenomena. These include the broad use of “cyberspace” and brick-and-mortar “cafes,” “chat rooms,” and, as the subtitle indicates, the “infobahn" that the internet was often called twenty years ago.

More broadly, writing in the time when the Internet had just been firmly established as a major mode of communication, Mitchell looked both around, surveying media contemporary to him, and ahead, speculating about future uses. Drawing on his architecture and urban planning expertise, one overall idea he promoted was that urbanism would be intensified through the expanding access to digital technology. Mitchell predicted numerous developments that did arise, such as the increasing importance of software and the ever-smaller size of electronic hardware.

Each of the seven chapters of this book explores significant aspects of the importance of environments in which electronic “mediation” occurs, and of adequate planning so that such environments will facilitate genuine human social interaction rather than wall people off. The chapters are titled "Pulling Glass" (concerned with laying fiber optic cables), "Electronic Agoras" (focusing on digital forums, such as cafes), "Cyborg Citizens" (focusing on the privileges and responsibilities of “netizens”), "Recombinant Architecture" (exploring building design, including office space and retail), "Soft Cities" (describing social media and networks), "Bit Biz" (focusing on ownership, control, and management), and "Getting to the Good Bits" (focusing on access to, sharing, and restricting digital information).