Redhat question

[Jes and guide dog Harley]

Hi all,
Well, thankfully I copied Redhat 9 over on to cdrw, so I can just diss that and rewrite the cd's with redhat 10 wit the speakup
images. But I had a question: How long, how consistantly does Redhat update to a new version? I've heard it was like every 6
months or so? And when I get redhat setup, can I just upgrade from the command line, or do I have to go and burn the install on
new cd's and completely trash the previous version in order to upgrade?
Thanks for any help.
Jes