Until this century, relative dating was the only technique for identifying the age of a truly ancient object.
This means that things like stone, metal and pottery cannot usually be directly dated by this means unless there is some organic material embedded or left as a residue.
Once the organism dies, it stops replenishing its carbon supply, and the total carbon-14 content in the organism slowly disappears.
Scientists can determine how long ago an organism died by measuring how much carbon-14 is left relative to the carbon-12.
As explained below, the radiocarbon date tells us when the organism was alive (not when the material was used).
This fact should always be remembered when using radiocarbon dates.