Audit log
The Audit log contains the complete history of every action that was performed on a record. A Timestamp, Event name, and User is recorded for each action. Both the Previous and New values for every property that changed when an action occurred are noted in the log:
From the Audit log pop-up, two buttons near the upper right allow the log to be either exported or filed as a record. For both cases, an HTML version of the audit log is used.