Fedora and RedHat Enterprise Linux-- what's the difference?

When you install a copy of linux on a hard disk, the main single task performed is the individual installation of "packages." A package corresponds to a single program or application, and is physically a wrapper file (similar to a zip or tar file) inside which are consolidated all the files that comprise and belong to that application. The installation CD holds perhaps thousands of these. When you install, you unpackage and deploy some or possibly all of them.

The major difference between the "workstation," "server," or "custom" installations offered by the installation program is the choice of which packages get installed. And a major difference between different distributions is the set of packages from which to choose offered on the CD.

Here is some empirical information that will allow you to compare Fedora Core 2 and RedHat Linux Enterprise ES 3. During installation a list of packages that get installed is automatically accumulated in /root/install.log. I installed both distributions, opting for "Everything" when it came to telling which packages to install. Thereupon, I was left with both a Fedora installation log, and an Enterprise ES installation log. I was interested in comparing them. To do so, for each distribution I generated a (approximate) list of packages it installed that the other didn't. Here are the packages in Fedora but not Enterprise, and packages in Enterprise but not Fedora. Roughly, Fedora 2 installs 1600 packages and Enterprise 3 installs 1100. Of these, 600 of Fedora's aren't in Enterprise, 100 of Enterprise's aren't in Fedora, and the other 1000 are in common between the two. (Update: Fedora 4's package count  is up to 1800.)

It's a little difficult to meaningfully interpret these crude lists of package names. In order to do so need to recognize or know something about what those packages are. (That information can be derived from the hundreds of package files themselves, on the installation CDs, but we don't do that here.) Broadly, things found in Enterprise but not Fedora are for enterprise-type purposes.

As for the 1000 packages common to both distributions, they are the same whichever distribution they're in. For example, both distributions give you the bash shell, the zip utility, the apache web server, the GNU c compiler, the mozilla web browser, the vi editor. There is only one apache web server, not two. There is only one zip utility, not two. So to the extent that the bulk of the contents of the two distributions amount to the same material, the distributions tend to be the same. (The "material" comes from distribution-independent sources. The progams mentioned here as examples don't come from "Enterprise" or "fedora" or "redhat." Rather, they are respectively originated and developed at:
 home of the bash shell: http://cnswww.cns.cwru.edu/~chet/bash/bashtop.html
 home of the zip utility: http://www.info-zip.org/pub/infozip/Zip.html
 home of the c compiler: http://gcc.gnu.org/
 home of the mozilla browser: http://www.mozilla.org/releases/mozilla1.4/
 home of the vi editor: http://www.vim.org/

When one studies the ins and outs of apache, it is not particular to Fedora nor Enterprise. Or if you prefer, it is applicable equally to both. Whether you boot Fedora and study apache there, or boot Enterprise and study it there. The apache about which you learn while you happen to be in Fedora is Enterprise's apache, and the bash shell you learn under Enterprise teaches you fully Fedora's bash shell. Because they are the same thing.

The differences between the Fedora and Enterprise distributions of linux aren't much about content and technology. They are about the surrounding business service issues of support, upgrades, training, services, documentation, and platform support. RedHat wants Enterprise to be above all reliable, bulletproof, ready for mission-critical settings. So they make sure the packages in it are a little more "mature," that is, a few versions behind, Fedora's. For example, again comparing Fedora 2 and its contemporary Enterprise 3, their respective versions of apache are 2.0.49 versus 2.0.46. For the mozilla browser, Fedora contains version 1.6 while Enterprise has 1.4.

Some discussion contrasting the Fedora and Enterprise distributions can be found in the textbook, RedHat Linux Bible, Fedora and Enterprise Edition. See the section "What is Red Hat Linux?" on pages 9-12, "...there is so much overlap between Fedora Core and Red Hat Enterprise Linux, Fedora Core provides a way to test out much of the software that is in Enterprise editions."

Finally you can go to the source and read what RedHat have to say for themselves about the differences. They document both Fedora and Enterprise on their website.