Upon startup, I get the following message:
 

dev/mapper/fredhost-root has been mounted 43 times without being checked. force check.

It boots fine, but I'm just wondering - what does that mean?

Thank you.

It means that filesystem has been mounted 43 times without being checked and a check is being forced.

Thanks. I'm a newbie. I understand when you plug in a flash drive you mount it in order to access the data. Are you saying the computer needs to mount the hard drive of the computer upon start up? This may sound naive but I'm new. Why does the computer need to run a check? Is there a need to prevent the computer from forcing a check? Should I care?

Thanks!

Yes, and the system usually automatically mounts the hard drive partitions for you. It runs a check after every X mounts just to be safe, because errors could have crept in. However if you always shut down your OS safely, the chances are unlikely. Let it run to be safe, or skip it if you're in a hurry.