Re: [exim] Defining "Virtual"

Quoting W B Hacker:

> ... domain
...
> ...servers, services, or whatever.
> Where is the 'virtual'?

Thinking of the historical meaning of a domain, where hosts in a network
are something like host.section.example.net, a
mail-/web-/$anyservice-server handling (*.)example.net (and probably
other domains) does not really contain contain the whole domain. I'd say
it's more like a proxy (with some added functionality) or a wrapper.
>From the outside, you don't know (and shouldn't care) if
some.host.example.org is real or ... virtual, yes. Virtual doesn't mean
that it doesn't exist. It just means there's something, but it may be
something else than it looks like. The extra layer handling the
virtuality makes its usage transparent.
Think of virtual memory: You don't know which real memory location you
are accessing, but you will surely access real memory (even if your data
has to be swapped in before to the location).