launchd

Manages processes, both for the system and users. You cannot invoke launchd manually, use launchctl to interact with it. More information: https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/Introduction.html.

Run init:

/sbin/launchd

View documentation for interacting with launchd using launchctl:

tldr launchctl