TL:DR 两者并无可比性. OAuth2 可以利用 JWT 作为 bearer token. OAuth2 包含的东西更多.
JWT is an authentication protocol
This means it is a strict set of instructions for the issuing and validating of signed access tokens. The tokens contain claims that are used by an app to limit access to a user.
OAuth2 is an authentication framework
OAuth2 on the other hand is a framework, think very detailed guideline, for letting users and applications authorize specific permissions to other applications in both private and public settings.