I googled the term, but I mostly got advanced hardware jargons about'em, what's your idea? How much difference? Which one's better in which field? Wuddya prefer for your job and why? I just want you to talk about it if you wish, you're gonna teach me alot if you do!

thank you,
bijan

Given the ridiculously high price of SCSI drives I don't want to know about them! They are supposed to be more reliable than IDE drives, maybe they are but not that it shows.

Their speed advantage has been cancelled by SATA drives. Personally I'd go for SATA every time.

This is a very personal opinion.

SATA:
http://en.wikipedia.org/wiki/SATA

SCSI:
http://en.wikipedia.org/wiki/SCSI

Well, I've a couple of Sparc machines at home that I can't make anything useful with because the SCSI drivers they have are too small and buying a new disk is way expensive for those old machines. I'd be so happy if I could put an IDE or SATA disk on them

Home users shouldn't bother with SCSI drives. They are made for high-end workstations and servers. Yes, they are fast, and yes, they are very powerful, but they also overheat very easily without a very well-ventilated case and given that most home users go for space over speed all of the money required for 30 gigabytes on a SCSI makes it not worth it.
I still use IDE. There are some lingering compatibility issues with SATA drives on some motherboards that I don't really want to deal with. I am planning to switch in 2-or-so years.