Visma Connect IdP OAuth 2.0 Authorization Server is issuing JSON Web Tokens (JWT): Tokens that conform to the JSON Web Token standard and contain information in the form of claims. These are self-contained which means it is not necessary for applications or APIs to call the server to validate the token. https://jwt.io/ can be used during development to verify JWT's claims.
There are different types of tokens that are issued to applications during the authentication/authorization process.