Debian GNU/Linux: Guide to Installation and Usage | Page 3

begin our journey down the road of GNU/Linux, we'd like to first talk a
bit about what exactly Debian is - what it does, and how it fits in with
the vast world of Free Software. Then, we talk a bit about the
phenomenon that is Free Software and what it means for Debian and
you. Finally, we close the chapter with a bit of information about this
book itself.
What Is Debian?
Debian is a free operating system (OS) for your computer. An
operating system is the set of basic programs and utilities that make
your computer run. At the core of an operating system is the kernel.
The kernel is the most fundamental program on the computer: It does
all the basic housekeeping and lets you start other programs. Debian
uses the Linux kernel, a completely free piece of software started by
Linus Torvalds and supported by thousands of programmers worldwide.
A large part of the basic tools that fill out the operating system come
from the GNU Project, and these tools are also free.
Another facet of an operating system is application software: programs
that help get work done, from editing documents to running a business
to playing games to writing more software. Debian comes with more
than 1,500 packages (precompiled software bundled up in a nice format
for easy installation on your machine) - all for free.
The Debian system is a bit like a pyramid. At the base is Linux. On top
of that are all the basic tools, mostly from GNU. Next is all the
application software that you run on the computer; many of these are
also from GNU. The Debian developers act as architects and
coordinators - carefully organizing the system and fitting everything
together into an integrated, stable operating system: Debian

GNU/Linux.
The design philosophy of GNU/Linux is to distribute its functionality
into small, multipurpose parts. That way, you can easily achieve new
functionality and new features by combining the small parts (programs)
in new ways. Debian is like an erector set: You can build all sorts of
things with it.
When you're using an operating system, you want to minimize the
amount of work you put into getting your job done. Debian supplies
many tools that can help, but only if you know what these tools do.
Spending an hour trying to get something to work and then finally
giving up isn't very productive. This guide will teach you about the
core tools that make up Debian: what tools to use in certain situations
and how to tie these various tools together.
Who Creates Debian?
Debian is an all-volunteer Internet-based development project. There
are hundreds of volunteers working on it. Most are in charge of a small
number of software packages and are very familiar with the software
they package.
These volunteers work together by following a strict set of guidelines
governing how packages are assembled. These guidelines are
developed cooperatively in discussions on Internet mailing lists.
A Multiuser, Multitasking Operating System
As we mentioned earlier in section 1.1, the design of Debian
GNU/Linux comes from the Unix operating system. Unlike common
desktop operating systems such as DOS, Windows, and MacOS,
GNU/Linux is usually found on large servers and multiuser systems.
This means that Debian has features those other operating systems lack.
It allows a large number of people to use the same computer at once, as
long as each user has his or her own terminal.1.1 To permit many users
to work at once, Debian must allow many programs and applications to
run simultaneously. This feature is called multitasking.
Much of the power (and complexity) of GNU/Linux systems stems
from these two features. For example, the system must have a way to
keep users from accidentally deleting each other's files. The operating
system also must coordinate the many programs running at once to
ensure that they don't all use the same resource, such as a hard drive, at
the same time.

If you keep in mind what Debian was originally designed to do, many
aspects of it will make a lot more sense. You'll learn to take advantage
of the power of these features.
What Is Free Software?
When Debian developers and users speak of ``Free Software,'' they
refer to freedom rather than price. Debian is free in this sense: You are
free to modify and redistribute it and will always have access to the
source code for this purpose. The Debian Free Software Guidelines
describe in more detail exactly what is meant by ``free.'' The Free
Software Foundation, originator of the GNU Project, is another
excellent source of information. You can find a more detailed
discussion of free software on the Debian web site. One of the most
well-known works in this field is Richard M. Stallman's essay, Why
Software