2.2.1 Overview of Debian packages
Packages generally contain all of the files necessary to implement a set of
related commands or features. There are two types of Debian packages:
Binary packages, which contain executables, configuration
files, man/info pages, copyright information, and other documentation. These
packages are distributed in a Debian-specific archive format (see Debian package format, Section 2.2.2); they are
usually distinguished by having a .deb file extension. Binary
packages can be unpacked using the Debian utility
are given in its manual page.
Source packages, which consist of a .dsc file
describing the source package (including the names of the following files), a
.orig.tar.gz file that contains the original unmodified source in
gzip-compressed tar format, and usually a .diff.gz file that
contains the Debian-specific changes to the original source. The utility
dpkg-source packs and unpacks Debian source archives; details are
provided in its manual page.
Installation of software by the package system uses "dependencies"
which are declared by the package maintainers. These dependencies are
documented in the
control file associated with each package. For
example, the package containing the GNU C compiler (
on the package
binutils which includes the linker and assembler.
If a user attempts to install
gcc without having first installed
binutils, the package management system (dpkg) will print an error
message that it also needs
binutils, and stop installing
gcc. (However, this facility can be overridden by the insistent
dpkg(8).) For additional details, see Package dependencies, Section 2.2.8 below.
Debian's packaging tools can be used to: