A change log is a record of all changes made to a system or application, including the date, time, description, and approval of each change. A change log can help an IS auditor to trace the source and authorization of a modification to a system's security settings. A system event correlation report is a tool that analyzes data from multiple sources to identify patterns and anomalies that indicate potential security incidents. A database log is a record of all transactions and activities performed on a database, such as queries, updates, and backups. A security incident and event management (SIEM) report is a tool that collects, analyzes, and reports on data from various sources to detect and respond to security incidents.