I'm trying to understand the difference between the following two terms:

*:80
_default_:80

in the Apache configuration file. The documentation here is unclear to me, and the only mailing list conversation that I could find here does not shed any (comprehensible, to me) light on the matter either.

I have a bunch of name-based virtual hosts declared like this:

<VirtualHost *:80>
    ServerName example.com
    ...

and I'd like to have an entry that fires when none of those match, i.e. when a request comes in without a virtual host name, or with a virtual host name that has not been declared. Should I use *:80 or default:80?