I am using an Ubuntu 20.04 VM in a Windows 10 machine using two network adapters, NAT and Bridged. However, in the "Network Connections" of the Windows 10 machine, I see "Ethernet4" which is a "VirtualBox Host-Only Ethernet" adapter. I can also ping this address.
But why is this adapter available even though I have no adapter of the VM set to Host-only? Maybe it is present all the time, but there is no "machine" behind this IP address?