Popup - A separate browser window opened on top of the previous one. * OAuth - More specifically OAuth 2.0, a standard protocol for authorization. See oauth.net/2/. * OpenID Connect - A layer on top of OAuth which standardises authentication. See en.wikipedia.org/wiki/OpenID_Connect. * JWT - JSON Web Token, a popular JSON based token format that is commonly encrypted and/or signed, see en.wikipedia.org/wiki/JSON_Web_Token * Scope - A string that describes a certain type of access that can be granted to a user using OAuth. * Access token - A token that gives access to perform actions on behalf of a user. It will commonly have a short expiry time, and be limited to a set of scopes. Part of the OAuth protocol. * ID token - A JWT used to prove a user's identity, containing for example the user's email. Part of OpenID Connect. * Offline access - OAuth flow that r