Stratified

Stratified is an adjective meaning arranged in layers or formed by layers. The term derives from strata, Latin for “bed” or “layer.” In various disciplines, stratification describes a layered structure or a process that creates layers.

In geology and earth science, stratified rocks are those composed of distinct beds laid down over time, such as sedimentary rocks. Stratification refers to the arrangement into layers, called strata; the study of these layers is stratigraphy, used to interpret geological history and relative ages of formations.

In biology and medicine, “stratified” describes tissues with multiple cell layers, such as stratified squamous epithelium, which provides protection for underlying tissues. Stratification can also describe the arrangement of cells, membranes, or organ structures in other anatomical contexts.

In sociology, social stratification describes structured inequality in a society, with citizens ranked in hierarchical layers based on factors like income, occupation, education, or status. This stratification influences access to resources and social mobility, and is a central concern of social theory and policy analysis.

In statistics, stratified sampling involves dividing a population into strata, or subgroups, before sampling. This method aims to improve precision by ensuring that samples reflect the population’s diversity on key characteristics.

In atmospheric science, the term can describe vertical layering of the atmosphere, such as the troposphere and stratosphere. In mathematics, stratified spaces are spaces decomposed into manifolds of varying dimensions, a framework used in geometry and topology.