Overview

They are essentially like a mailing system

Advantages

• More efficient than doing constant request pulls

Disadvantages

• The API provider is responsible for failures and retry policies
• App running behind firewalls can send, but receiving can be tricky
• A webbook is a single event. So many events in a short time can be noisy

• The client tells the API provider which events it is interested in and also the callback URL to send the data back to the client
• Whenever there are event updates, the API provider sends a POST request to the URL provider.