Stable vs Release vs Current

[David Beukes]

Hi,

Have been using FreeBSD for about a year now but haven't
understood or found a definitive answer to the
versions/branches. Would appreciate it if someone could
shed some light; a bit of history follows:

I installed 1st FreeBSD system from 4.4 (the only cds I
could get my hands on). By the time I started understanding
what I was doing, 4.8 was out. So I CVSup'd the source and
did the whole make buildworld/installworld kernel thing.
And I was running 4.8... Question here is, was I running
4.4 release? or 4.4 stable? when did 4.8 become stable (are
you starting to catch my drift?).

Then in December 2003 (about a month after 4.9 was
announced), I downloaded ISOs for 4.9 and reinstalled from
scratch. Same questions as before, am I running 4.9 stable?
release? When did release become stable?

Am now running 4.9 and started cvsupping the source. my
supfile has this line in it: default release=cvs
tag=RELENG_4_9. Am I wasting my time? Should it rather read
RELENG_4? If so, why?

And where do security patches fit into this story? 

Any info would be helpful.

Thanks,
David