Really, there are only a few different modifiers.

First, Wide/Narrow doesn't affect anything else. Narrow was the ``norm''; everything past Ultra2 is wide-only. Wide doubles the bandwidth as well as doubling the number of available IDs from 8 to 16 (really 7 to 15, since one is always used by the controller itself).

The other portion of the name determines the bandwidth. It just goes SCSI (5MB/s)/Fast SCSI (10MB/s)/Ultra SCSI (20MB/s)/Ultra 2 (40MB/s)/Ultra 160/Ultra 320/Ultra 640. You'll note that the bandwidth between Ultra 2 and Ultra 160 quadruples. That's because of the transition to no narrow buses; the prior ones are based on the narrow bandwidths. Obviously, they realized that they couldn't keep coming up with more superlatives, so they switched to numbering, then they realized that the numbers might as well have some meaning. They'll probably switch to something else the next time. Honestly, I don't think it's any harder than remembering PIO/DMA/UDMA/ATA100/etc. for IDE buses, not to mention not needing an add-on protocol like ATAPI.

Then there's the cabling. HVD (high-voltage differential) is very uncommon. About five years ago it was simply uncommon, but I've only ever seen it once. That just leaves LVD (low-voltage differential) and single-ended (SE). These have to do with the electrical level of the protocol. Most LVD devices will work on an SE bus, but revert to SE mode. You saw some of both in the Ultra days, but before that it was basically all SE and after it's all LVD.