Sediments are reliable records of changes in physical, chemical, and biological conditions that take place before, during, and after their deposition and express the changes through constituent mineralogical and thus geochemical compositions. Individual sedimentary events create more or less homogeneous bulk chemistry of sediments at varying temporal and spatial scales. Distinguishing these homogeneities and for classification of stratigraphic records and correlation of the strata at varying spatiotemporal scales is emerging to be a reliable method of stratigraphy and is termed as chemostratigraphy a la chemical stratigraphy. This method helps stratigraphic correlation with ease where other formal stratigraphic methods have limitations or fail to achieve required spatiotemporal resolution.The study of geochemical variations in stratigraphic context has gained importance since the 1980s. Chemostratigraphy is, thus relatively a younger branch of geosciences. Attempts on distinguishing depositional units at varying spatiotemporal scales (from local to global and from tidal cycles to few tens of millions of years) have been influenced to a larger extent by the sequence stratigraphic concepts. Contemporaneous developments in sophisticated instrumentation for fast, accurate, and less expensive geochemical analyses have also contributed to the popularity and applications of chemostratigraphy. From a humble beginning of identification of similar geochemical values and similar pattern of geochemical profile, chemostratigraphy has traveled a long way. Currently, a wide variety of techniques and data from other subdisciplines of geosciences are used for distinction/recognition and correlation chemozones/geochemically distinguishable depositional units.Yet, chemostratigraphy consists of vaguely defined and often misleading and/or overlapping terminologies. Through an extensive review of published literature, this chapter attempts to enlist these terminologies namely, chemostratigraphy, chemical stratigraphy, geochemical fingerprinting, geochemical signature, geochemical fingerprint, geochemical marker, geochemical proxy, excursion, shift, fluctuation, perturbation, anomaly, trend, chemostratigraphic index, chemozone, chemochron, resolution, and scale of correlation and provides definitions/explanations. This attempt is made for initiating discussion among the practitioners that may lead to consensus on definitions and standardized usage.Despite, fulfilling the criteria required for any standard stratigraphic method and finding its applications in many different fields, this method/tool remains to be formally given its due. Elucidation of the traits and enlisting the terminologies of chemostratigraphy with the criteria for formal recognition prescribed by International Stratigraphic Commission suggests that chemostratigraphy deserves to be formalized as an independent stratigraphic method. © 2015 Elsevier Inc. All rights reserved.