Organized levels of authority, importance.

A hierarchical organization or hierarchical organisation (see spelling differences) is an organizational structure where every entity in the organization, except one, is subordinate to a single other entity.

In data mining and statistics, hierarchical clustering (also called hierarchical cluster analysis or HCA) is a method of cluster analysis that seeks to build a hierarchy of clusters.

a system of grouping things according to a hierarchy.

Structured data organized in levels.

Organizing networks in logical layers.

Organized, multi-level navigation interface system.