iTunes works at its best when there is a single user on a single computer. Here is s bummer: what if you just bought a new laptop, and you want to transfer iTunes library to new PC? You want all your well organized music playlists and videos held by your iTunes library on your old PC to be transferred to your new laptop (PC or Mac) exactly the way you see it on your original machine?
There was no easy answer to the above situation, at least not until recently. You would have had to move the entire iTunes folder system (and this includes moving it to the exact same location of your new computer). Make one mistake, and you risk ruining your iTunes library.
There is a good an easy way that I use to transfer and backup my entire iTunes library from my old PC to my new computer. The program which allows transfer and backup of iTunes library from PC to PC and transfer iTunes library from PC to Mac is called CopyTrans TuneSwift.