With an API, one system asks another. A webhook works the other way round: the system itself announces that something happened - a payment came in, a form was submitted, an order changed status.
What it is used for
Automations that should run right away. After payment an invoice is issued, after a form submission a contact is created in the CRM and a sales rep gets notified.
What to keep in mind
A webhook can arrive twice or not at all when the other side is down. A reliable automation expects that and can recover the missing message.
