Windows Event Viewer is a built-in tool in the Windows operating system that allows users to view and analyze event logs on their computer. These logs record various system, security, and application events, helping users troubleshoot issues and monitor system performance. The Event Viewer categorizes events into different logs, such as Application, Security, and System. Each log contains detailed information about events, including timestamps, event IDs, and descriptions, making it easier for users to identify problems or understand system behavior over time.