Difference Between API And Webhook

API

• An API is a set of programming instructions and standards for accessing a web-based software application or web tool. 
• In other words, an API serves as a communication channel between two software pieces.

Webhook

• A webhook is a user-defined callback over HTTP, usually triggered by an event. 
• When that event occurs, the source site makes an HTTP request to the URL configured for the webhook.
• That request typically contains event data, allowing the destination site to take appropriate action.

Differences

• Webhooks are typically used to send real-time data, while APIs retrieve data on demand.
• The key distinction between APIs and Webhooks is that APIs enable two-way communication, while Webhooks allow one-way data sharing triggered by events.
• The backend service (some API) where the request will be processed is necessary to consume the webhook.
• An XML or JSON format is used to send the webhook POST payload.
• Alternatively, it might be delivered as form data, using an encoding like `multipart/form-data`.