AFAIK=as far as I know
WVO/SVO=waste veggie oil or straight veggie oil. This fuel in unrefined. The nasties are filtered out and the water is usually allowed to separate, but that's it. Most, but not all, systems running this fuel will require two tanks, one for diesel and the other for the veggie oil. The vehicle is started on diesel and allowed to warm up while also warming up the veggie oil via coolant heat exchangers. Heating up the oil thins it out to the point that it is injectable. A series of valves are switched and the engine is then allowed to run on the heated veggie oil until shut down when the valves are then switched back and the engine allowed to run long enough to clear the lines of veggie oil.
Biodiesel=waste veggie oil that has been refined, usually through titration with methanol and lye. The end result is a fuel that is usable as is without the need for a second tank or heating. Various states have different mandates for differing amounts of bio to be added to dino diesel resulting in B5 (5% bio) on up to B100 (100% bio). Engine manufacturers certify their engines for a certain percentage.
In either case the risk of gelling is greater for both as I stated before. I know my engine is particularly cold blooded. If I used my veggie heat exchanger during the winter there might not be ANY heat left over for the cabin. As it is it won't make enough heat at idle to keep the thing warm during the winter.