systemd.target — Target unit configuration
target.target
A unit configuration file whose name ends in
                .target encodes information about
                a target unit of systemd, which is used for grouping
                units and as well-known synchronization points during
                start-up.
This unit type has no specific options. See systemd.unit(5) for the common options of all unit configuration files. The common configuration items are configured in the generic [Unit] and [Install] sections. A separate [Target] section does not exist, since no target-specific options may be configured.
Target units do not offer any additional
                functionality on top of the generic functionality
                provided by units. They exist merely to group units via dependencies
                (useful as boot targets), and to establish
                standardized names for synchronization points used in
                dependencies between units. Among other things, target
                units are a more flexible replacement for SysV
                runlevels in the classic SysV init system. (And for
                compatibility reasons special
                target units such as
                runlevel3.target exist which are used by
                the SysV runlevel compatibility code in systemd. See
                systemd.special(7)
                for details).
Unless DefaultDependencies=
                is set to false, target units will
                implicitly complement all configured dependencies of
                type Wants=,
                Requires=,
                RequiresOverridable= with
                dependencies of type After= if the
                units in question also have
                DefaultDependencies=true.