No it's completely different to drilling the airbox. All it involves is removing two restrictive pipes that are attached to the inside of the airbox. I found personally that it doesn't seem to do anything but some people claim it does.
One bloke reckons he gained 1.5-3bhp on his corsa gsi, but it is very highly tuned.
It's such a simple and easy mod that it's worth doing just on the off chance that it might give some gains for you.
See the tutorial.
different airboxes for most of the range, theres a fair few different types ive seen, mines got an air valve in mine to take heat from the exhaust manifold if the intake air is too cold, but all thats been skipped anyway lol.