Transfering files from computer hardrive to My Book?

Can anyone help me??

I have just purchased a My Book and wanted to move my itunes directory from my computers hardrive to my My Book.  I am currently backing up the files accordingly, but wondered?  Are the files just being duplicated or actually moved?

I want to increase my computers speed, by moving others files across as well.

Can anyone help me on this??  Obviously I don’t want files duplicated, as there would be no point in that, hence me buying a My Book.

Any help would be greatfully apreciated.

Thanks

Tadge

I am pretty sure that when you perform a Backup - you are copying files from one place to another.