Hierarchy

1. A hierarchy (in Greek hieros, sacred, and arkho, rule) is a system of ranking and organizing things.
2. A group of people, or things arranged in order of rank or grade.
3. A system of dividing people or things into rank
4. An ordering of groups in which larger groups encompass [phone number lookup] sets of smaller groups.
5. Any system where there is a parent-child relationship.
6. A group of people, ideas, objects, etc. arranged in a graded series (high to low, good to bad, etc.).
7. In computer science's object-oriented programming, the mapped relationships of sub- and superclasses is known as a hierarchy.

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