What type of information is contained in /var/log/messages?

The file /var/log/messages serves as a central repository for global system messages, which includes a variety of information generated by the system and applications. This encompasses everything from system startup messages and general operational statuses to service start and stop notifications, hardware errors, and any other significant events that might require attention.

This log file is crucial for system administrators because it provides an overview of system activities and can help in diagnosing problems or monitoring the system's health. While kernel logs and warnings, application service names, and authorization logs might be valuable, they are typically categorized in different log files or sections specific to those areas (like /var/log/kern.log for kernel messages, /var/log/auth.log for authentication events, etc.).

Thus, the comprehensive nature of /var/log/messages as it pertains to global system messages makes it the correct answer.