What do GDM logs primarily contain?

GDM logs primarily contain GNOME session-related messages, which are critical for the operation of the GNOME Display Manager (GDM). These logs provide insights into user sessions, including login attempts, session starts and ends, and any issues encountered during the graphical session. This information can be particularly useful for diagnosing problems related to the graphical user interface, user authentication into the GNOME environment, and the start-up behaviors of graphical applications.

The other options refer to different types of logs that serve other purposes. System health reports are typically more general and related to overall system performance or monitoring, rather than GDM's specific focus. General system messages can include a wide variety of logs generated by different system components, but do not specifically target GNOME sessions. Kernel boot messages deal with logs generated during the system's boot process, providing information about the hardware and services initialized by the Linux kernel, not user session management. Thus, GDM logs are distinct in that they focus specifically on user interactions within the GNOME desktop environment.