OAuth1 and OAuth2

You might find different version of OAuth on social media platforms: OAuth1 and OAuth2. OAuth2 is a fully rewritten improved version of OAuth1. It defines four roles for client, authorization server, resource server and resource owner while OAuth1 uses different concepts to describe the roles. There are also multiple technical differences related for example to cryptography, but a complete analysis is beyond the scope of this chapter. We can conclude that OAuth2 is slightly less complicated and easier to use.