What exactly does the webbook mean?

One of the ways in which a server that provides Web services delivers an event to the outside world.

For example, if there is a service that provides a bulletin board,

Whenever a new post is posted on a bulletin board, it can be useful when you want to notify a particular notification to another service or messenger.

In the above situation, the new article is registered in the bulletin board must be found out to follow up.

If you can hook for an action (new post registration in the above example) in the bulletin board service, you can handle the above situation.

Here, the web hook can be seen as providing the previous hooking in the web environment.

You must first provide the functionality to hook into the service (the bulletin board service above). I think webhook is the way to create a service that you want to handle by hooking and registering this service URL with the information service like the previous bulletin board service.

In general, web services are requested by the side that needs information as a client, whereas webhooks are requested in the opposite direction. The side that needs the information becomes the server, provides the endpoint address to the service, and the service can think of it as a way of disclosing what information it can give.