could anyone briefly explain to me the differences and similarities between these 2 operating systems?

Wow, where does one begin?

It's the same basic operating system - the GNU operating system with a Linux kernel. Whatever applications you can find in RedHat you will probably find in Debian too (unless they have license problems) since Debian has an enormous package repository. You may have to look at the Testing (currently called "Sarge") or Unstable (always called "Sid") Debian distribution to find really current versions. IMHO Debian is very easy to maintain although some find the lack of a pretty graphical installer and wizards to do stuff for you is revolting. RedHat is very user-centered. For most things you can think of doing there is a graphical interface of some sort.

I'll stop here, I can't really make either distribution justice. Try both and stick with the one you like the most.


Håkan

I think the two biggest differences you will notice off the bat are:

Installing:
Redhat has a nice gui, and version 9 autodetects almost all of your hardware. Also makes it easy to install X and KDE or gnome.
Debian is a consol based install, and requires that you know more about your hardware.

Software:
Rehat uses rpm, Debian uses apt-get. I found apt-get more friendly when dealing with dependencies, but this was just my experience.


Overall, I think if you go debian, be prepaired to do a tad of reading. Redhat is easy, but you may (as I did) feel in the dark about what is going on. I think debian gave me a better experience, but I had the time.