I am currently running Corel Linux. I have heard that it is based on Debian. I am thinking about going to Mandrake, which I heard is based on Red Hat. What does that really mean, that they are based on other versions? Are Debian and Red Hat the two versions that all other are built from?
I'm sure this has been discussed, but I searched and couldn't find it.
thanks

They are all the exact same in the fact that they are Linux distros since they use the Linux kernel. Differences are in what the system is based on. For example FreeBSD uses the BSD (Berkley Software Devel.) base. It's just what each distro decides to use as it's "glue" in a sense as i finger it...

Each distro operates differently. Debian and Red Hat have different ways of installing files. Debian has its .deb packages while Red Hat has its .rpm's. Most of the time though you can make any distro look and feel like any other cause they all are based on the exact same kernel. So you can use the same window manager and shell on Debian as you can on Red Hat. Mandrake and Corel just took the distros and altered some of the aspects that make it unique like installation method and default window manager and shell. Otherwise they are mostly the same. There may be some differences here that I haven't explained like Debian is better for servers. Well I hope this helped. If anything is wrong or someone disagrees with it this is only what I think the differences are.

Ofcourse theyre the same in using the Linux kernel (else it wouldnt be Linux), but their base version may differ.
A basic difference can be in how some distro's incorporate custom patches to fi. better detect/support hardware (Mandrake, raid support, IIRC), and in their choices of application/library support versions (Red Hat, 7.0, GNU Gcc compiler), and how/if they adhere to the filesystem layout (location of files, directories and configs as in the Linux File Standard FHS), and how they do package/system management(think YAST2, Linuxconf, or the stuff from Progeny Linux).

It's not like Debian or Red Hat are the base for other distro's. And even if it happened to be that way ppl wouldnt want to know, distro pride 'n all :-]