cvsup....base and prefix???

[Aaron P. Martinez]

I have successfully used cvsup a few times now...and i am comfortable
with what the base and the prefix do.  

My question is why would someone put things in different locations than
for instance........./usr for both base and/or prefix?  

I have seen a few different options used both in the cvs up faq on the
cvsup homepage, the handbook and also in "the complete freebsd"  they
all have different places listed..but not one single place is any
discussion about the theory or logic behind where it is placed.

This is really just a "help me understand the philosophy" question as it
seems that no matter where i place my 'base' and 'prefix' paths..the
cvsup will work...just trying to get a grasp on _why_ i would want it
one place more than another.

Thanks in advance,

Aaron