Access token - A token used to access protected resources.
Authorization code - An intermediary token generated when a user authorizes a client to access protected resources on their behalf. The client receives this token and exchanges it for an access token.
Authorization server - A server which issues access tokens after successfully authenticating a client and resource owner, and authorizing the request.
Client - An application which accesses protected resources on behalf of the resource owner (such as a user). The client could be hosted on a server, desktop, mobile or other device.
Grant - A grant is a method of acquiring an access token.
Resource server - A server which sits in front of protected resources (for example “tweets”, users’ photos, or personal data) and is capable of accepting and responsing to protected resource requests using access tokens.
Resource owner - The user who authorizes an application to access their account. The application’s access to the user’s account is limited to the “scope” of the authorization granted (e.g. read or write access).
Scope - A permission.
JWT - A JSON Web Token is a method for representing claims securely between two parties as defined in RFC 7519.