Final answer:
Biostratigraphic correlation, part of relative dating, uses fossils to match and correlate rock layers from different locations to establish their relative ages and understand speciation rates.
Step-by-step explanation:
The concept of relative dating that refers to the process of matching similar fossils from different locations is known as biostratigraphic correlation or stratigraphic correlation. This method involves using fossils to establish the relative age of rock layers and to correlate between different geographic locations. If different sedimentary rocks contain the same fossils, it's likely that they were deposited during the same time period.
This allows geologists to determine which of two fossils is older or younger than the other, but it does not provide the exact age in years. Stratigraphy, which is closely related to the law of superposition, aids in assigning relative ages to fossils as well as understanding the geological history and rate of speciation of early organisms.