What does cvs admin -l do for me?

[Sandra Humphrey]

I have search the archives and I know that locking files has been
brought up in the past.  According to the manual, -l will lock the
latest revision number.  But, in the next paragraph it states that I
need to use rcslock.pl to have a reserved checkout.  I am confused on
what exactly the -l option would do without the use of the rcslock
command.

Our process dictates that we only let one person work on a file and so
we need this functionality.

Thanks.
Sandra