Hierarchy.
A level is a sub category of a hierarchy.
Levels have a specific order with a parent-child relationship.
In a Pivot Table, a single-level hierarchy will be displayed as a flat attribute while a multi-level hierarchy will display the first level and allow users to expand each member against the next level and display sub totals.
For example, a Geography hierarchy can have a Continent as the top level where Continent expands to Country which in turn expands to the leaf level: City.
atoti.Level
Level of a