The virtual reality netrunner space visited by V in Cyberpunk 2077 is called Cyberspace. It is a digital environment accessed through advanced neural interfaces and is portrayed differently from ordinary physical locations in Night City.
V enters cyberspace during story sequences involving netrunning, artificial intelligence, and the Blackwall. These scenes help explain how digital consciousness and networked entities exist beyond the ordinary city environment.
Mikoshi is a specific Arasaka digital storage facility, while the Blackwall is a protective barrier separating the usable Net from dangerous rogue intelligences. The Afterlife is a physical nightclub, so it is not a cyberspace location.