linux: added debian an apt (minor and major) upgrades

wiki/linux/package_manager.md

@@ -2,6 +2,45 @@
 
 Package managers are important programs to get software onto your system.
 
+## Debian & Debian-Based Systems: APT
+
+In [Debian](/wiki/linux/debian.md) the APT package manager is used.
+It is also used for various Debian-based distributions.
+
+### Debian: Usage
+
+This section addresses various usages of the APT package manager.
+
+#### Debian: Updating & Upgrading
+
+This section addresses the updating of all packages managed by APT.
+To update the packages it is recommended to first update the package list with the following
+command.
+
+```sh
+apt update
+```
+
+Afterwards there are two possible update types without changing the major release version.
+
+The following command - `upgrade` - updates the packages only if no new or previously removed dependencies are
+needed.
+It is generally used for day-to-day updating without bigger jumps between versions.
+
+```sh
+apt upgrade
+```
+
+The other option is `full-upgrade` which was previously also known as `dist-upgrade`.
+This command will also install, remove and replace dependencies if it is needed to update the
+package.
+It is mostly used for bigger updates like Kernel or release upgrade without changing the major
+version.
+
+```sh
+apt full-upgrade
+```
+
 ## Arch Linux: Pacman and Yay
 
 In [Arch Linux](/wiki/linux/arch-linux.md) there are 2 main types of