A webhook tells another system when an event happens, while an API lets it read data or request an action. Together they can turn a completed order into a customer-record update.
In the demo an order event is delivered, the first attempt fails, and a retry with the same event ID records it only once. Real systems need signature checks, retries, and duplicate handling too.
Receiving a webhook does not prove the follow-up action completed. Track processing status separately to detect loss and repeated work.
When to use
Use it to connect events and actions across systems, including failure and duplicate paths.