[nprateem]

The point is JWTs can be validated independently on the server, no DB lookup is required. In distributed systems, that's the main benefit - they don't all need to talk to the auth server, just have a certificate that can be used to validate JWTs. This means they can't be practically invalidated per user though.

By contrast, refresh tokens go to the auth server that can do whatever checks are necessary to make sure the user is still allowed to use the service. This would typically incur DB lookups and require more complex auth logic than simply validating "yeah, this JWT is legit and still in-date".