Relative dating includes methods that rely on the analysis of comparative data or the context (eg, geological, regional, cultural) in which the object one wishes to date is found.
Chronology is the science of measuring time and ordering of the things in time.
Relative techniques can determine the sequence of events but not the precise date of an event, making these methods unreliable.
b) Absolute These methods are based on calculating the date of artefacts in a more precise way using different attributes of materials.
Cross-dating of sites, comparing geologic strata at one site with another location and extrapolating the relative ages in that manner, is still an important dating strategy used today, primarily when sites are far too old for absolute dates to have much meaning.
The scholar most associated with the rules of stratigraphy (or law of superposition) is probably the geologist Charles Lyell.