The type of system unit to create. The selected type controls the filename suffix and the type-specific section written to the unit file. Created system units are written below /etc/systemd/system.

service creates a guided [Service] unit for starting and supervising a process. timer creates a [Timer] unit that activates another unit on a schedule. socket creates a [Socket] unit for socket activation. path creates a [Path] unit that reacts to filesystem changes. target creates a grouping or synchronization point for other units.

mount creates a [Mount] unit for a filesystem mount, and automount creates a matching [Automount] unit that activates a mount on demand. swap creates a [Swap] unit for swap space. slice creates a [Slice] unit for resource-control grouping and cgroup policy.

Scope and device units are normally created by systemd, udev, or other programs at runtime. They can be inspected when listed by systemd, but they are not created as persistent unit files here.