Absolute and relative rock dating
The primary difference 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.
Scientists base absolute dating on measurable physical or chemical changes or on written records of events.Using these methods, the scientist determines a date range for when an event took place rather than where it fits in the overall record. The techniques scientist need for absolute dating did not become available until the later half of the 20th century.