vBulletin uses PHP and MySQL.
No other software compares. Not even Invision Power Board.
Although they both seem so similar now, and IPB's admin panel is a lot more organised, Support and pricing - and security of vBulletin rates much higher, indefinatley.
One of the best things about vBulletin is that you need no PHP or SQL knowledge to run it, not even to add modifications. It uses a "plug-in" system that means no file editing for hacks and such.
You'll understand it all a bit more when you've read the
Instruction Manual for vBulletin.
There's also an
Admin Demo, so you can check out some of the features and get a little taste of what having vBulletin is like.
As for phpBB, it is well known for its bad security, it's always getting hacked into.