Can you describe what a webhook is and how it works in the context of system integration?

A webhook is a callback mechanism that allows one system to notify another about the occurrence of a specific event in real-time.

How it works:

1. The recipient system (for example, your service) provides a URL to which the sender system will send HTTP requests when an event occurs.
2. When the event happens, the sender system makes a POST request to this URL with data about the event.
3. The receiver processes the request and performs necessary actions (for example, updating data, starting a process, etc.).

Example: when a payment is made for an order, the payment system sends a webhook to your server so you can immediately update the order status.

Webhooks are convenient for integration because they allow data to be received without constant polling, saving resources and reducing delays.