Is VMware's VCenter installed on bare metal, or is it also possible on the host axis?

Question

Virtualization

I'm trying to figure it all out.

Answer 1

VCenter is not put on bare metal at all.
ESXi - hypervisor for virtualization of machines (hosts)
VCenter is a tool for configuring and managing ESXi + orchestration + much more, but it controls ESXi that is installed on bare metal or running under another hypervisor (nested virtualization).
VCenter exists as an installer for Windows or as a ready-made virtual machine (apliance).
As far as I remember, only apliance is supported in the latest version.
Total:
ESXi - bare metal or a virtual machine.
VCenter - host OS (Windows) or virtual machine.