[Plugin: WordPress MU Domain Mapping] server requirements

I’m trying to put down a comprehensive list of requirements for a WP multi-site multi domain network, but I don’t seem to be able to find it.

As far as I can understand, such a network works with one ‘main domain’ with a WP installation in its hosting package. After I set this up correctly and install and configure the domain mapping plugin, I can use other domains to link to that WP install. In other words, I do not need other hosting packages and databases for these websites I will be mapping to the main domain. Is this correct?

http://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/