The trigger is what starts a flow. Without a trigger, there is no flow: it answers the "when X happens".
Trigger types
- CRM events: new contact, new order, conversation created, deal moved between stages.
- Marketing events: campaign activated, inbound lead with ad source.
- Webhooks: an external app notifies the flow's URL.
- Scheduled: runs at a fixed time (daily, weekly, at an exact hour).
How to pick a good one
An effective trigger is specific: not "every message", but "message from a new contact". That way the flow does one thing well and does not overrun.