Relative dating methods in archaeology
Very often historical evidence is found in layers and older layers are further down that the top layers.For example: If an archaeologist is studying past civilizations, the archaeologist may be able to say that in a particular location the ruins of one civilization were found to have been built on another and so the layers unearthed in an excavation convey the sequence of historical occupations without revealing the actual dates.
Short Answer: The term relative dating is distinguished from absolute dating to make it clear that one does not get a specific estimate of the age of an object from relative dating, but one does get such an estimate of true age from absolute dating.
There are several techniques employed in both sets of methods. Long Answer: Sciences such as geology, paleontology and archeology are very interested in identifying the age of objects found and these scientists sometimes use both relative dating or absolute dating to characterize the age of the objects they study.
However, carbon dating is an absolute dating technique that can give an estimate of the actual age of an artifact and thus an estimate of the age of other objects in the same layer.
Carbon dating is one example of radiometric dating.
Before radiometric dating (or other methods of absolute dating like counting tree rings) it was difficult to determine the actual age of an object.Radiometric dating, based on known rates of decay of radioactive isotopes in objects, allows a specific age of an object to be determined to some degree of accuracy.