launchd is a "system wide and per-user daemon/agent manager." It is a daemon that handles daemons. Use launchctl to interface it.
Configuration files
launchd uses plist files to know how to interact with each installed daemon/agent. It is explained here.
Configuration file locations
| Location | Type |
|---|---|
| /Library/LaunchAgents | Administrator controlled Agents for a specific user |
| /Library/LaunchDaemons | System-wide daemons provided by the administrator. |
| /System/Library/LaunchDaemons | Default daemons provided by iOS. |