Queen bees are born that way due to special care and feeding while they are developing larvae. They are larger than the worker bees and are able to control the hive via pheromone signals. When they first take flight, they mate with Drone bees (the only males in the whole hive), whose sole purpose is to fertilize Queens (they die after that).
After that one mating flight, the Queen then spends the rest of her life laying eggs and never needs to mate again. If she becomes sick or dies, the hive will feed some larvae so that they develop into new Queens and one will hatch and take the old Queen's place.