Andrew Nacin who is one of the core developers of WordPress has published a post that should have come with a package of Tylenol. The post goes into the reasons behind why the terminology within WordPress MU was changed and why it’s created a soup of confusion. I’ve read the post three times in a row and it still hurts my head to try and make sense of it all.
When the merge began, the core developers began to use multisite internally to mean many blogs (well, sites), shortened to “ms” where possible, thus removing the “mu” and “wpmu” prefixes on files and functions.
Surely, we can make this more difficult. And so, just as the UX decision was made to call a blog a site, we decided to call a multisite a network.
So if you’re wondering why things are named the way they are in the merged edition of WordPress MU, give his article a read. Bonus points if you can read it once and not get lost.