https://www.bleepingcomputer.com/news/microsoft/microsoft-adds-systemd-to-the-windows-subsystem-for-linux/

Microsoft and Canonical have teamed up to add systemd support to the Windows Subsystem for Linux, allowing a larger number of compatible apps to be installed.

systemd is a Linux software application that acts as the system and service manager for initializing daemons/services during the bootup of the operating system. Systemd also supports tools that allow Linux admins to easily manage and control these services after they have been started.