apt-get(8) dist-upgrade
APT package handling utility - - command-line interface
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. So, dist-upgrade command may 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.
source manpages: apt-get