Is there a difference between the webhook and postback patterns?

At work I often see people talking about the webhook and postback patterns interchangeably, I'd like to know if there is a difference.

I've also noticed two patterns:

1. There's one in which you send an HTTP request to an endpoint stating through a header field an address to which the result of the asynchronous operation should be sent;
2. Another one in which you previously set an address to which the results should be sent. And then, on your HTTP requests, you will not inform this address again, but the results will be sent to the address previously configured.

Could anyone explain the difference, if there is any?

Thanks in advance.