Without getting too carried away, there are a number of handy commands that will tell you certain attributes regarding the current state of your system (admittedly, some of them are Red Hat-specific). Some of this information is definitely handy if you have to get help troubleshooting over the phone, for example.
$ who who's logged in? $ hostname print the host name $ arch print the architecture> $ cat /etc/redhat-release print current (Red Hat) OS release $ uname -a print various system info $ cat /proc/version print kernel version
Even if you can't appreciate some of the above just yet, remember how to get this information. Guaranteed, it will come in handy at some point.
The uname command comes with a number of options for seeing much more specific system information, such as:
$ uname -n nodename $ uname -m machine hardware name $ uname -p processor type $ uname -i hardware platform $ uname -o operating system $ uname -s kernel name $ uname -r kernel release $ uname -v kernel version $ uname -a all of the above
To see all of the possible options for uname, check its man page.