UNIT                                                                                                    LOAD      ACTIVE   SUB       DESCRIPTION
sockets.target                                                                                          loaded    active   active    Sockets
sound.target                                                                                            loaded    active   active    Sound Card
swap.target                                                                                             loaded    active   active    Swap

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

xxx loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.
