The Queen - 1 per colony
The queen bee is the leader of the bee colony. She is the only fully mature female bee in the colony and is usually the mother of all the other bees. The queen is recognisable from other bees because she is the longest bee in the hive. Her wings extend about half the way along her abdomen, which is pointed at the rear. Her head is proportionally small for her body.
The queen's main purpose in life is to reproduce. A good queen will lay around 2,000 eggs per day (which a chicken would take over 6 years to produce!). She is, in fact, a terrible mother, having completely lost any instinct to care for her young. The queen relies on the female worker bees to raise her young. She controls the workers' behaviour by producing pheromones which affect their behaviour.
The Workers - 10,000 - 50,000 per colony
The worker is the smallest bee and is about half the weight of the queen and drone. The abdomen is pointed and the wings are short. Female worker bees literally work themselves to death over the course of their lives. They provide food for grubs, drones and the queen bee and build the wax honeycomb that forms the hive's integral structure.
In fact, they are model citizens - they clean, ventilate, defend and repair the hive, and most ingeniously of all worker bees are experts in air conditioning. They keep the hive at a constant temperature of around 34'C. If the colony is too hot, they douse their bodies in water and bring it into the hive. They then work together to fan the air with their wings, thus bringing the temperature down by evaporation. In cooler times, they huddle together around the brood of eggs to keep it warm. Once a worker bee reaches the end of her useful life, she drops dead, to make way for new, younger workers to emerge.
The Drones - 1000 per colony
A drone is a male bee. It is about the same size as the queen but is much more squarely built. His wings completely cover his abdomen and his large round head is distinctive for its two eyes which meet at the top. He has no sting. Male bees appear to have a very easy life. They do not work in the hive, do not forage for food, cannot defend the hive (as they have no sting) and are looked after by the workers who feed them honey. Their one purpose in life is to mate with the queen, after which they die. They do not survive over winter and any that are left in the hive in the autumn will be escorted out by the workers (girl power?)