In an earlier version of GNOME System Monitor on lubuntu there was an addition tab, "System" which displayed some handy system information in a single location including Ubuntu version, Linux kernel version, amount of RAM and processor info.
How is this available now? Since the info was there in a previous version it seems like the complete removal of the tab would have been replaced by some other method of providing the same functionality. This is useful by providing GUI users a simple way to report basic info about their system to support people.
NOTE: The above is from an htorque ask ubuntu answer.