An authentication layer built on top of OAuth 2.0

Resource Owner

The entity that can grant access to a protected resource. Typically this is the end-user.

Resource Server

The server hosting the protected resources. This is the API you want to access.

Client

The app requesting access to a protected resource on behalf of the Resource Owner.

Authorization Server

The server that authenticates the Resource Owner, and issues tokens.

Authorization

Used to interact with the resource owner and get the authorization to access the protected resource.

Token

Used by the application in order to get an Access Token or a Refresh Token.
(Not used in Implicit Flow)

Authorization Code

An opaque string, meant to be exchanged with an Access Token at the token endpoint.

Access Token

An opaque string or JWT that denotes who has authorized which permissions (scopes) to which application.

Refresh Token

A special kind of token containing the information required to obtain a new Access Token or ID Token.

Id Token

A JWT that contains user profile information (name, email, etc.), represented in the form of claims.

Authorization Code

Authorization Code with Proof Key for Code Exchange (PKCE)

Implicit

Client Credentials

OAuth 2.0 Official Website

https://oauth.net/2/

OAuth 2.0 Complete Guide

http://bit.ly/oauth-complete

OAuth 2.0 Scopes

http://bit.ly/oauth-scopes