dist-upgrade, full-upgrade

From what I can determine, these two commands do the same thing:

# apt-get dist-upgrade
# apt full-upgrade

The following appears to work the same as the above commands as well, although the option is not explicitly defined in man apt:

# apt dist-upgrade

This is because most (if not all) apt-get commands can also be used as apt commands.

From man apt-get:

       upgrade
           upgrade is used to install the newest versions of all packages currently
           installed on the system from the sources enumerated in
           /etc/apt/sources.list. Packages currently installed with new versions
           available are retrieved and upgraded; under no circumstances are currently
           installed packages removed, or packages not already installed retrieved and
           installed. New versions of currently installed packages that cannot be
           upgraded without changing the install status of another package will be left
           at their current version. An update must be performed first so that apt-get
           knows that new versions of packages are available.

       dist-upgrade
           dist-upgrade in addition to performing the function of upgrade, also
           intelligently handles changing dependencies with new versions of packages;
           apt-get has a "smart" conflict resolution system, and it will attempt to
           upgrade the most important packages at the expense of less important ones if
           necessary. The dist-upgrade command may therefore remove some packages. The
           /etc/apt/sources.list file contains a list of locations from which to
           retrieve desired package files. See also apt_preferences(5) for a mechanism
           for overriding the general settings for individual packages.

From man apt:

       upgrade (apt-get(8))
           upgrade is used to install available upgrades of all packages currently
           installed on the system from the sources configured via sources.list(5). New
           packages will be installed if required to satisfy dependencies, but existing
           packages will never be removed. If an upgrade for a package requires the
           remove of an installed package the upgrade for this package isn't performed.

       full-upgrade (apt-get(8))
           full-upgrade performs the function of upgrade but will remove currently
           installed packages if this is needed to upgrade the system as a whole.