Carbon-14 is a weakly radioactive isotope of Carbon; also known as radiocarbon, it is an isotopic chronometer. C-14 dating is only applicable to organic and some inorganic materials (not applicable to metals).

What would C14 dating be used for?

Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.