Tools in the category of radiometric dating are based on the known rates of radioactive decay of isotopes and this allow some samples to be assigned a certain age to within some accuracy.
By using the known decay rate of C as a reference and working out how much of the fossil's composition consists of C and how much of it consists of N, they can approximate the age. C has a half life of years which means that only half of the original amount is left in the fossil after years absolute and relative dating ppt half of the remaining amount is left after another years. This type of dating employs many dating techniques like atomic clocks, carbon dating, annual cycle methods, and trapped electron method.
Any technique that assigns a certain age or date is a form of absolute dating.
Relative dating is any scientific process of evaluation used to determine the relative order of past events, but does not determine the absolute age of an object.
The primary difference in relative dating and absolute dating is that absolute dating assigns an actual time or age to an event or object.
Relative dating simply says one is older than the other but no age is specified.