absolute age(true age) The age of a geologic phenomenon measured in present Earth years, rather than its age relative to other geologic phenomena (compare relative age)
Relative age is the age of a rock layer (or the fossils it contains) compared to other layers. It can be determined by looking at the position of rock layers. Absolute age is the numeric age of a layer of rocks or fossils. Absolute age can be determined by using radiometric dating.
