Scopes vs. claims: What they are, how they differ, and when to use each

Scopes and claims are integral yet distinct components in the OAuth 2.0 and OpenID Connect frameworks, each serving unique purposes within the authorization process. Scopes function as permission requests, representing broad categories of access that a client application seeks on behalf of a user, and they are presented during the authorization request. These scopes determine which claims, or factual assertions about an entity such as a user, are included in a token. Claims are more granular and are embedded within tokens, providing specific data like user identity or email, which the authorization server issues and resource servers later validate for access. While scopes outline the types of access a user consents to, claims deliver the actual data once access is granted, with their relationship ensuring that only necessary information is shared based on the granted permissions. Understanding the differentiation and interplay between scopes and claims is crucial for developing effective and user-friendly authorization models.