Question about partitioned hard drive

I have a G5 1.6 160 gig hard drive. The person I bought this computer from has the hard drive partitioned into two parts. What's the advantage to this? I'm not even sure how to use the second hard drive or what to use it for. However, the first partition is almost at capacity right now. I'm not sure what kind of files I can save to the second hard drive. I'd love to have all of my itunes music files stored in the second hard drive, but I'm not sure how it would still link up to the itunes program, if I moved the files. Any help, suggestions etc.. would be appreciated. Thanks in advance!

I would say that the two partitions are for file organization. May the previous owner used the second partition for his/her data. I that make it easier in some case for back up purposes. As for your iTunes data, since I only have seven songs on my system. I will leave that for someone else, with better knowledge to answer.