from
The Free On-line Dictionary of Computing (8 July 2008)
virtual host
vhost
<networking> Most computers on the {Internet} have a single
{IP address}; however, often via special {kernel}
patches, a given computer can be made to respond to several
{IP} addresses and provide different {services} (typically
different {Web} services) on each. Each of these different IP
addresess (which generally each have their own {hostname}) act
as if they were distinct hosts on distinct machines, even
though they are actually all one host. Hence, they are
{virtual} hosts. A common use is when an {Internet Service
Provider} "hosts" {World-Wide Web} or other services for
several of their customers on one computer but giving the
appearence that they are separate servers.
(1997-09-11)