Describing Linux and Linux Distributions

Usually people understand Linux to be an entire package of developer tools, editors, GUIs,
networking tools, and so forth. More formally, such packages are called distributions. You
may have heard of the Linux distributions named Red Hat, SuSE, Mandrake, and Caldera,
which have received a great deal of press and have been purchased for thousands of installations.
Noncommercial distributions of Linux such as Debian are less well known outside certain
technical circles, and while they have many happy users, they haven’t reached the same scale
of popularity as the commercial distributions.

What’s interesting about all Linux distributions is that almost all of the tools with which
they ship were not written by the companies themselves. Rather, other people have licensed
their programs, allowing their redistribution with source code. By and large, these tools are
also available on other variants of UNIX, and some of them are becoming available under
Windows as well. The makers of the distribution simply bundle them up into one convenient
package that’s easy to install. (Some distribution makers also develop value-added tools that
make their distribution easier to administer or compatible with more hardware, but the software
that they ship is generally written by others.)

So if you consider a distribution to be everything you need for Linux, what then is Linux
exactly? Linux itself is the core of the operating system: the kernel. The kernel is the program
acting as Chief of Operations. It is responsible for such tasks as handling requests for memory,
accessing disks, and managing network connections. The complete list of kernel activities
could easily be a module in itself, and in fact, several books documenting the kernel’s internal
functions have been written.

The kernel is known as a nontrivial program. It is also what puts the Linux into all those
Linux distributions. All distributions use the exact same kernel, and thus the fundamental
behavior of all Linux distributions is the same.

What separates one distribution from the next is the value-added tools that come with each
one. For example, Red Hat includes a very useful tool called redhat-config-xfree86 that makes
configuring the graphical interface a very straightforward task. Asking “Which distribution is
better?” is much like asking “Which is better, Coke or Pepsi?” Almost all colas have the same
basic ingredients—carbonated water, caffeine, and high-fructose corn syrup—thereby giving
the similar effect of quenching thirst and bringing on a small caffeine-and-sugar buzz. In the
end, it’s a question of personal preference.