What is an Endpoint?

Question

I have been reading about OAuth and it keeps talking about endpoints. What is exactly an endpoint?

Answer 1

Endpoint, in the OpenID authentication lingo, is the URL to which you send (POST) the authentication request.

Excerpts from Google authentication API

To get the Google OpenID endpoint, perform discovery by sending either a GET or HEAD HTTP request to https://www.google.com/accounts/o8/id. When using a GET, we recommend setting the Accept header to "application/xrds+xml". Google returns an XRDS document containing an OpenID provider endpoint URL.The endpoint address is annotated as:

http://specs.openid.net/auth/2.0/server 
{Google's login endpoint URI} 

Once you've acquired the Google endpoint, you can send authentication requests to it, specifying the appropriate parameters (available at the linked page). You connect to the endpoint by sending a request to the URL or by making an HTTP POST request.