I'm not surprised there's some confusion over snapshots and VCs, and for age I've argued that Adobe should merge the two concepts. Snapshots are OldThink for those who use LR with a single-image Photoshop mentality, while VCs are more appropriate to LR's multi-image role (eg a b&w version of an entire shoot) but are let down by not saving to xmp data and perhaps cluttering up your Library with thumbnails. It's also worth pointing out that this isn't just about adjustments but VCs can have different IPTC metadata. Rather than dance on a pinhead and try to explain the two logically, I think it's better to list their different features, strengths and weaknesses - and acknowledge that there is some redundancy / messiness. Whether it's really worth Adobe tidying this up, when there's so much else they should have done in Library....