The Audit Trail helps you track the recent Setup changes that you and other administrators have made to your organization. This is especially useful in organizations with multiple administrators. The setup Audit Trail history shows you the 20 most recent Setup changes made to your organization.
It is a security-relevant chronological record, set of records, and/or destination and source of records that provide documentary evidence of the sequence of activities that have affected at any time a specific operation, procedure, or event.