For example, the grains within a sedimentary rock are older than the rock; a fragment of sandstone incorporated within a mudstone is older than the mudstone; a fossil bone found in a limestone is older than the limestone.

What is the difference between relative and absolute aging?

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.