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.
Therefore, we can obtain numeric dates of many rocks that represent important events in Earths distant past.
However, prior to the discovery of radioactivity, geologists had no proven method of numerical dating and instead had to rely solely on relative dating.
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.
Essentially, relative dating places rocks in their proper sequence of formation, e.g. Although relative dating cannot give us numeric dates for events that took place, it does provide useful information on what event followed or preceded another event.