This tag is for questions about Windows' Event Viewer and Event Logs. Event Viewer is where Windows stores logs generated by the Operating System and certain applications.
Event Viewer has three primary logging areas:
Recent Versions of Windows (Vista and later / Server 2008 and later) have a large number of additional log areas.
Most Windows components (such as services) log to the System log, with notable exceptions being IIS and user-related operations (such as folder redirection at login) which log to the Application log. Programs that you write should log either to their own log areas or to the Application log. The Security log records successful and failed logins.