Providing isolation for VirtualBox Host Only Adapter issue resolved.

[Kaltiro]

Hello friends, my questions are as follows:

1) How does the combination of Host-Only adapter and NAT provide security and isolation compared to using NAT alone?
2) Does the combination of Host-Only adapter and NAT completely prevent software or programs from reaching the HOST machine?
3) How exactly does the Host-Only adapter work and what kind of isolation does it create?