LaunchAgents are macOS's built-in system for running background tasks. They replace cron, are more capable, and integrate deeply with the OS. Every Mac has hundreds of them running right now.
launchd is PID 1 on macOS — the first process, parent of everything. You give it a job description (a plist file), and it manages the lifecycle: starting, stopping, restarting, scheduling, and resource management.
Two flavors:
- LaunchAgents — run as your user, in your login session. Can access your files, GUI, keychain.
