What is a webhook?

A webhook is fundamentally understood as a user-defined HTTP callback that is triggered in real-time based on specific events or conditions. When a defined event occurs in the source system, the webhook sends an HTTP request to a predefined URL in your application. This allows for immediate data transfer or action, such as updating a database or notifying a user, without requiring a constant polling mechanism.

The appeal of webhooks lies in their efficiency and responsiveness; they allow systems to communicate and react to events as they happen, rather than waiting for a scheduled check. This technology is widely used in various applications, from payment processing to content management systems, enabling automated workflows and real-time updates that improve user experience and operational efficiency.

Understanding this concept is crucial for working with modern APIs, as webhooks often provide a seamless way to integrate and respond to different services without excessive overhead or latency. Other options, while related to API structures or functionalities, do not capture the specific real-time, event-driven characteristic that defines a webhook.