A:AnswerThis drive has no cache and WD is sourcing multiple drives so you could get a 4800RPM like me or a 5400RPM. If you're looking for a fast drive this is not it sadly.
A:AnswerThe last 4 characters are explained here https://products.wdc.com/library/other/4579-705045.pdf
Basically, the SN means Standard, and BB is BestBuy. So the WEBB model is one sold solely through BestBuy.