Which of the following is a function of an error log?

An error log serves a crucial function in monitoring and maintaining the health of server operations by documenting issues that arise during those operations. When server errors occur—such as failed requests, failed connections, or application faults—the error log captures these events along with relevant information, which can include timestamps, error messages, and sometimes the stack trace. This information is vital for system administrators and developers as it helps them diagnose problems, troubleshoot issues effectively, and maintain the overall reliability and performance of the server.

In contrast, the other options highlight functions that are not part of an error log's purpose. Recording page load times pertains more to performance logging, detailing request origin relates to access logs, and summarizing user engagement statistics falls under analytics or tracking logs. Therefore, the role of the error log is distinctly focused on capturing errors and operational issues rather than these other areas.