社会の階層について研究している。
I am researching social strata.
この組織は階層がはっきりしている。
This organization has a clear hierarchy.
They analyzed society by dividing it into several strata.
The positions in the organization form a clear hierarchy.
Employees in the upper tier have decision-making authority.
Even those in the lower tier were given a chance to voice their opinions.
階層 means a social class or hierarchical layer, while 断層 means a fracture or rift; they share the kanji 層 but differ in meaning.
階層 is the neutral term for a stratum or hierarchical level in general, whereas 下層 specifically names the lowest one.
mono-hierarchy
poly-hierarchy; multiple hierarchy