API vs WebHook

Webhook vs. API What's the difference and when should you use each one

Webhooks and API calls are very familiar to each other, the key differences is that Webhooks are a event driven message, while a API is a ongoing communication.
Webhooks don't expect a response beyond a succeed or failed message, whilst API is more for ongoing communication, as it can send something like a User ID generated from a API endpoint that creates a new user.

Kind of similar to UDP vs TCP. If Webhooks are UDP, its because they just want to send a message and don't care after it has been released.
API would be like TCP, as it has handshakes a long the way and points of interaction to make sure everything is working.

An API is something you call to. For example I ask the Facebook API for a list of my friends or ask it to post to my wall.
A webhook is something that calls to you. So I could ask Facebook to let me know when a new friend request comes in or when I receive a new private message.
Webhooks save you from having to poll their system constantly. Imagine asking if you have a new message every 10 seconds vs just being told the second it happens.
What's the difference between a webhook and api? : r/webdev