Anyhow, to answer your question. In .Net, a collection is an object, just like anything else in .Net, so you can create your own destiny for this collection of controls. You can't do that in VB6 without a lot of work to hack around and make it OOP-like.
Inheritance nad polymorphism and just a couple of OOP techniques that can be applied with/to a any .Net object. These things, again, are not available in VB6 unless you hacked your way around and made something similar.
I'm by no means an expert in explaining all this, as you can tell, but perhaps it makes alittle sense.
The sample provided in that link shows how to properly create a Collection with the .Net resources. You don't have to manually dispose of items (supposedly) beceause of the built-in Garbage Collection - admittedly the garbage collection does do it's job, lots better than any previous MS garbage collection imho.
Sounds like you should pick up a book on Object Oriented Programming to ge ta better understanding of it. I have a decent A-Press book for C# - it's title is something to do with building classes in C# (don't have the book in front of me) but it's indeed helpful.
Sorry for the babbling and ignore this if it is complete and utter tripe.