cvs: newbie question rtag vs. tag

 
I know obviously that some commands w/ the Rs in them are due to RCS like rlog and log.  
 
for cvs rtag and cvs tag ... is it the same difference?  rtag tags the repository and tag the working directory.  I was tagging the HEAD as the final build to use later as a branch point if necessary.  I used rtag.  just making sure I am correct.
 
Sorry for so many quesitons.
KM