A ''source package'' is the source archive of which on or more binary packages can be compiled. Those binary packages are most often referred to as just packages. 

Example: from [[https://launchpad.net/ubuntu/+source/nautilus|the source package 'nautilus']] the following binary packages are compiled:
 * libnautilus-extension-dev
 * libnautilus-extension1
 * nautilus
 * nautilus-data
 * nautilus-dbg

== Finding the source package ==
You can find the source package of a certain package with:
 * The search box at the home page of [[https://launchpad.net/ubuntu|Ubuntu in Launchpad]]
 * The command {{{apt-cache show ${package name} | grep ^Source:}}}
  * ''If you get nothing from the previous command, the package name is the same as the name of the source package.''