Resin. It is a plant resin that bees collect. It can have antibacterial and immunostimulant properties. The problem is that it varies from region to region and by bee species. You can be allergic to it also.
Maybe, but unproven. Propolis is a substance made by bees (out of plant nectar & sap) to seal parts of their hive. Placed on herpes sores, some studies have claimed better healing. However, propolis is not a single item, because bees just use what they can find for their hives. Propolis is different in different hives, even in different parts of one hive, and especially in different parts of the country or the world.