Log files can be really helpful when troubleshooting a problem. In your class linux machines take a look in /var/log to see all the great logging going on with our systems. In fact, one of the major reasons I switch from Windows to Linux when I was younger was because I could diagnose system difficulties far more easily in linux then I could in windows. As an administrator, diagnosing problems is a daily chore. ;)

So give a few examples of some logs , what type of information is stored in that log, and how you could use that information to diagnose a problem.