Editing APT (software) (section)

==Configuration and files==
<code>/etc/apt</code> contains the APT configuration folders and files.

<code>apt-config</code> is the APT Configuration Query program.<ref>{{cite web|url=https://manpages.debian.org/unstable/apt/apt-config.8.en.html|title=apt-config(8)|website=Debian Manpages|access-date=18 December 2021}}</ref> <code>apt-config dump</code> shows the configuration.<ref>{{cite web|url=http://www.debianadmin.com/query-apt-configuration-using-apt-config.html|title=Query APT configuration using apt-config - Debian admin|date=2 December 2006 |access-date=18 December 2021}}</ref>

===Files===
* <code>/etc/apt/sources.list</code>:<ref>{{cite web|url=https://wiki.debian.org/SourcesList|title=SourcesList|website=Debian Wiki|access-date=18 December 2021}}</ref> Locations to fetch packages from.
* <code>/etc/apt/sources.list.d/</code>: Additional source list fragments.
* <code>/etc/apt/apt.conf</code>: APT configuration file.
* <code>/etc/apt/apt.conf.d/</code>: APT configuration file fragments.
* <code>/etc/apt/preferences.d/</code>: Directory with version preferences files. This is where "[[#APT pinning|pinning]]" is specified, i.e. a preference to get certain packages from a separate source or from a different version of a distribution.
* <code>/var/cache/apt/archives/</code>: Storage area for retrieved package files.
* <code>/var/cache/apt/archives/partial/</code>: Storage area for package files in transit.
* <code>/var/lib/apt/lists/</code>: Storage area for state information for each package resource specified in <code>sources.list</code>
* <code>/var/lib/apt/lists/partial/</code>: Storage area for state information in transit.