I ran chkdsk /r last night on my primary HDD and it reported and allegedly "recovered" (I think) 4 bad sectors. What does that mean and is there any way I can tell exactly what it did and did not do?

It seems that every time I run a chkdsk, at the end it'll say that there are errors in the volume bitmap and that I should use chkdsk /f (requiring a reboot if boot drive). Is it because there is a ...