The Egyptian Social Pyramid is the representation of the social structure of Ancient Egypt. The structure is not completely rigid, with some exceptions and blurred lines. But the basic concept is based on the division of classes which was organized by status and power.
The reason it's similar to a pyramid is because the majority of the population had the least amount of power. They were the skilled and unskilled workers. At the bottom-most, the farmers and workers that built the houses and monuments had the toughest working conditions. They worked long hours and were paid the least.
Contrary to popular belief, there were no slave workers in Ancient Egypt. War prisoners and criminals were forced to work (which in a way is a form of slavery). Even the pyramid builders were Egyptians that worked on the building for about 3 months of the year and were paid for their work.
Usually these were the farmers that worked the fields, but as the Nile flooded the land for 3 months of the year, they were effectively out of work for that period of time. These were the same people recruited to build the pyramids and other monuments during that time.
So after the working class there are the noblemen, elite, and the ever-powerful priesthood. Of course there are social classes within this class too (just as there are classes within the working class). Not all priests or nobles had equal power.
The population of this class is significantly smaller than the working class.
Then it's the Vizier, the second most powerful man in all of Ancient Egypt. It may seem odd to have a class composed of only 1 person, but the difference in power and status is what differentiates him from the rest.
And then finally, it is the almighty ruler and pharaoh of Egypt – the King.