As I type this I am sure it's a silly question, but I am totally uninformed so I must ask! Can someone please explain the differences, as I am sure when my ROFR passes (let's hope) I will need to unload points now and again.
Transferring occurs between DVC owners. You can transfer some of your points, once per UY, to another member. Per the regulations, you are not allowed to receive compensation for this (although many do). Once points are transferred, they are the property of the owner who received them and in their control. The original owner of the points can not get them back.
Renting happens when you make a reservation on your membership and then rent out that reservation to someone else for a price. It could be another DVC owner or a non-DVC owner.
However, you continue to own the reservation and have total control over it, including the ability to cancel or change it. Per our regulations, you are allowed to collect fees for this as long as you are not conducting it in a commercial way--so far, it appears that DVC considers reservations in other's names, around 20 times per year, as a possible indication that commercial renting is going on.
Another point about renting, the owner of the points is also responsible for the actions of the renter. If the renter damages the room or leaves an unpaid balance, Disney's interest is with the owner and will have no issues with restricting the use of the points until they are paid. In the end, Disney really doesn't care you rented your points, that care that you own them.
Renting happens when you make a reservation on your membership and then rent out that reservation to someone else for a price. It could be another DVC owner or a non-DVC owner.
A big difference is that in transfer arrangement, you need to transfer the points and collect your money. Risk - Disney will not do anything if the customer does not pay and you have already transfered the points, since this transaction is against their rules.
In a rental you need to 1) contact MS to see if there is availability, 2) make the reservation, 3) make any changes to the reservation (adding DDP), 4) hope the renter does not do anything stupid ( you are on the hook for renter stiffing Disney on a room charge, or damages to the unit). Disney will not stick up for you if the renter does not pay. You will need to cancel the reservation and hope you have enough time to bank or re-rent the points.
There are many successful rental stories (most of them) but there is increased hassle and risk with rental.