Webhook

A webhook is a way for one application to send real-time data to another when a specific event occurs. Instead of constantly checking for updates (polling), the sending system pushes a notification the moment something happens, like a payment completing or a form submission arriving. Webhooks are the event-driven glue of modern integrations.

The everyday comparison: polling is phoning the post office every hour to ask if your parcel arrived; a webhook is the delivery driver ringing your doorbell. You have probably benefited from one today — when a customer pays through Stripe and a confirmation email goes out seconds later, or an online order instantly appears in your fulfillment app, a webhook fired the moment the event happened and set the rest in motion.

Why it matters for your project: webhooks are the backbone of the automations that save small teams real hours. "When someone books, add them to the CRM and notify the team channel." "When an invoice is paid, mark the job ready to schedule." Each of those starts with a webhook. When scoping an automation project, the practical question is which of your tools can send webhooks and which can receive them — that determines what can happen automatically versus what still needs a human to copy data across.

Webhooks are the push-based counterpart to a regular API, where your system must ask for updates; most real integrations use both, and the APIs involved typically follow REST conventions. Well-built webhook handlers also verify signatures and handle retries, so a brief outage does not silently swallow an order.