woody sarge and sid
 

what are the main features and differences among the tree releases?

http://www.debian.org/doc/FAQ/ch-ftp....html#s-stable

Woody: well tested and stable, software tends to be behind
Sarge: the next stable release, reasonably tested packages and fairly up to date
Sid: an utter mess of the latest and greatest packages, do not use it unless you are familiair with the risks.
Experimental: don't go there...still, some do....

As someone else pointed out, see: http://www.debian.org/releases/

I have heard someone say a good naming system would be:

"stable" = "server" (well tested, very stable, but old versions of everything)

"testing" = "workstation" (newer programs, a few bugs but pretty stable)

"unstable" = "geek" (the latest available stuff, but can have major problems crop up that is difficult for a new user to fix)