1. What is the difference between a transfer and a trade?
A transfer is when points actually move from one member account to another. If I transfer pts to you, you can control them you can call
DVC member services (MS) and book a reservation with those pts and make changes to that reservation if needed. You can bank transferred pts (but not borrow them). You are only allowed one transfer (either in or out, but not both) per UY.
A rental is when I use my pts to book a reservation for you. I can rent that reservation to a DVC member or a nonmember. I still control the reservation until you check in. You cannot call to cancel or change the reservation MS will not discuss the reservation with you even if you are a DVC member.
A trade is usually when I book a reservation for you and you book a reservation for me (usually at each others home resorts). That would work more like a rental, and due to the lack of control and risk of being the party traveling last, trades are pretty rare from what I understand. The one transfer per UY means trades involving transferred pts are also pretty rare but theoretically you could trade your current UYs pts out and accept the other members next UY pts in.
2. How does a transfer work?
An example of a transfer is when I call up MS and tell them to give X number of my OKW pts from my 2013 Oct UY to you. You would then be able to call up MS and book OKW at 11 months out since the transferred pts home resort and UY remain attached to the pts.
Technically, I should add that accepting compensation for a transfer is prohibited in the contract.
3. How does a trade work?
As I mentioned, barters are complicated (how many OKW pts does it take to equal a BLT pt?) so most people deal in cash