VisualStudio is sort of a collective term for all of these.
Now closing in on version 2005 (when was this written? Well, I guess it's something like version 8 if you're counting), VisualStudio has been the standard in IDEs for a long time, with a interface that countless people have tried to copy (all pretty much unsuccessfully), and rather high responsiveness.
It doesn't stop there, though. You can make macros in VisualBasicScript? to give it some cool functionality, like format your code or automagically add characters/comments etc. You can even make add-ons using the ComponentObjectModel? (COM) if you need more functionality.
VisualStudio and its compilers are often though of as the same things. However, the compilers are usually command-line programs which are launched as a child process by either visual studio itself or visual studio's special process launcher (VCSPAWN.EXE in 6).
Personally, I'm a version 6 fan -- the newer interface is a bit too techno-ish for myself and is a bit slower than 6. -- RyanNorton