Becoz feudalism is the the dominant social system in medieval Europe, in which the nobility held lands from the Crown in exchange for military service, and vassals were in turn tenants of the nobles, while the peasants were obliged to live on their lord's land and give him homage, labour, and a share of the produce, notionally in exchange for military protection.
Apartheid caused separations between races. Non-whites were moved out of white areas and into rural areas. There were even wealth separations between these groups, as the government saw that white people as being more superior to the non-whites.
