...

A REST interface receives the webhook, conducts a procedure based on its content and provides a response.

...

Graph 1: Webhook functionality

The Trigger

Typically the webhook is sent in response to a change in the source application's data. The creation or update of an entity that needs to be either synchronized with another integrated application or for simply logging purposes in an external system. When such a triggering event happens in the source system, the external REST server will be contacted, usually with an API entity ID of the created/updated entity.

...