itunes

I have a itunes folder in the music folder in my computer under the "home" directory and I have an itunes folder under HD. Is one of these simply a copy or duplicate and if so how would i determine, or should their be two folders of itunes and my music collection??

thanks-

The one under the HD contains plug ins etc that are system wide.
The iTunes folder under your account is yours..

You have System Files including a Library
Then HD files that are for all users which includes a Library
Then your account just for you which includes your Library
All are necessary.
S.