What is the difference between bee pollen and royal jelly?

Bee pollen and royal jelly are two entirely different substances, both being products of the beehive. Many people still assume that anything extracted from the hive is basically the same substance under a different name. Clearly that is not the case.
To form a clearer picture of what each substance is, one needs to consider the source and how it came to be within the beehive. Royal jelly is secreted from glands located in the heads of the common worker bee. The substance is then fed to all bee larvae, which is the term used to refer to the embryo or egg as it goes through different stages in the life of bees and other insects. Whether they are destined to become drones (males), worker bees (sterile females) or queen bees (fertile females) all larvae are fed on royal jelly. The drone and worker larvae are taken off their royal jelly diet after around 3 days, but queen larvae continue to be fed the substance through all stages of their growth and  development.
In a natural environment, a hive functioning without human intervention, the substance is available in only a very small quantity. Where a beehive is 'farmed' and designated for royal jelly production, the beekeeper stimulates the colonies with movable frame hives to increase the production of the queen bees in the colony.  Once the queen larvae reach about four days old the substance is collected from each individual queen cell or honeycomb, since only these specific cells have sufficient quantity of the deposited substance. During a typical hive production season of six months, a farmed beehive can produce around 500 grams of royal jelly. Considering the substance is generally sold in its fresh liquid state, or in 1000mg capsules, it's clear that a considerable number of beehives are required for a commercial royal jelly operation. (If one hive produces 500 grams in six months, that is only sufficient to produce 500 1000mg capsules, with a commercial value at the manufacturing end of the sales funnel of only a few dollars US).

So that's royal jelly, now what about bee pollen, how is it different.

Pollen grains or 'granules' are comprised of the male germ cells produced by plants and  flowers. Bee pollen is composed of microspores produced in the anthers of flowers and in the cones of conifers, which are taken by the bees and used to create the pellets of bee pollen, or the bee pollen granules, each of which may contain upwards of two million spores of plant pollen. The honeybees transfer the pollen from the anther of a stamen to the stigma of a pistil which subsequently provides the fertilization component and leads to the growth of the seed. So in essence, the pollen granules are particles collected from plants and synthesized by worker bees. Incidentally, the worker bees are all females and there are around 30,000 or so per hive colony. The drones are all males whose sole function is to mate with the newly born queen bee.