Contrary to John and Cletus.. I actually use
both snapshots
and VC's, as they're
both equally useful to me.
I use a plugin by (the late/gone-missing) Rob Cole, called "Snap and Mark", that is able to put the copy name in front of the snapshots' names. (FYI: And ANY other metadata that one may wish, in any order/format. And has MUCH more flexibility than the TPG version - not to mention it's FREE. It can be a bit more geeky to set up, though. Unfortunately, like "TPG LR Backup", both of them are now abandoned-ware.)
Snapshots are useful for keeping one development 'line' that I may want to branch out from, but don't deserve a VC in their own right. And once I decide I may want to fork an image (an obvious example being black-and-white - but also low&high clarity, and low&high vib-saturation versions), I'll create a VC from one of those 'base lines'. And further snapshots on the VC's, as well (possibly to spawn yet more VC's). The snapshots on the VC's will also serve to embed them into the XMP within the main [DNG] file.
So, for snapshots, I may have:
"m(for master).YYMMDD.HHMMSS. CUST-text" and:
"Copy 1.YYMMDD.HHMMSS. CUST-text"
Etc...
(And often for the custom text, I'll put a shorthand of what was changed since the previous snapshot: "1.01 b, det, gr, br, rad". Meaning: Version 1.01, basic panel, detail panel, grad, brush, radial.)
Snap-and-Mark can prompt for a custom text to either put in the snapshot name, or simply marking the edit history with, or both.
(And I use Snap-and-Mark so often that I even have the keyboard shortcut to it tied to my middle mouse buttons while in LR.. On top of being set as a radial option in Wacom prefs.
)
Snapshots can also be useful to serve as a sort of round-about 'layers' mechanism.. Like if you have a ton of spot removals, but find that they slow things down too much - one can do a 'copy' on just the spot removals, reset the image, paste the spot removals, THEN create the snapshot of them. (Obviously, one doesn't really
need to reset the image to use them in this way - but doing so will allow for all-around smaller file sizes.)