The social hierarchy is a hierarchical structure of relations of power, income, prestige, etc. The social hierarchy reflects the inequality of social statuses.
Many organizations, such as business companies, churches, armies, and political movements, are hierarchical organizations (at least officially). Usually the elders, called «bosses», have more power than their subordinates. Thus the relationships that define this hierarchy are «command» or «power».
A lot of public criticism is caused by the existence of hierarchies that are unfair according to one’s point of view. Feminism, for example, often discusses a gender hierarchy in which male or masculine traits are seen as dominant over female or feminine traits.
It should be noted that in this context and others like it, the word «hierarchy» is usually used as meaning «hierarchy of power» or «power structure». Feminists and representatives of other social movements, for example with a racist or anti-gay bias, may not agree with the hierarchy itself, as such, but rather with a certain asymmetry, unequal value of men and women, different races, etc.
Anarchism, and other anti-authoritarian social movements, seek to eliminate all hierarchical social relationships.