Automation, jobs and integration
A job is a trigger, conditions and an ordered list of actions, set up under Customization › Orchestration in the admin; jobs were called hooks before the module was renamed, and the API's routes keep that name. What starts a job, what it can do, branches and loops, email, scheduled work, integrations with other systems, and every event and action.
Every event that can start a job and every action it can run. Jobs were called hooks, and the API's routes still use that name.
Job event reference lists every event that can start a job, one entry each: what fires it, what it carries, its loop risk, and an example. Job action reference lists every action type a job can run, one entry each: what it takes, what it leaves in the batch for later actions, and when it fails.
Read either page to look up one entry; read the rest of the guide first for how to choose between them.