+A **stratum** (plural: strata) is a distinct layer, often one of several, arranged in a sequence. It can denote a natural [geological layer](/wiki/geological_layer) or a division within a [social structure](/wiki/social_structure).
+## See also
+- [Layer](/wiki/layer)
+- [Sedimentation](/wiki/sedimentation)
+- [Hierarchy](/wiki/hierarchy)
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