The bees collect nectar and turn it in to honey, which they make to store as their food source for over winter. If there is more honey than the bees need, we spin it out of the comb and jar it up. You can't tell how much honey the bees will make each year because it greatly depends on the weather and what flowers there are.
There has been a lot of press recently about the plight of bees - many beekeepers have lost colonies, due to the poor summers we've had and the build up of a mite called varroa. This mite lives on bees and if not controlled, the population becomes so great that it kills the colonies. The British Beekeeping Association is lobbying for the government to invest more money in to the research of bee health. Basically, if there are no more bees, mankind won't have food. Scary thought.