Identity answers the question who are you? It is necessary but not sufficient: knowing who is asking does not decide what they may do. That is the job of delegation and policy.
Identity
The verified answer to "who is this?" for a person, an AI agent, a service or an organisation making a request.
Example
A request arrives from Sarah’s Claude connection. Kroy knows the person is Sarah, signed in through Microsoft Entra ID, and the agent is her Claude client, a distinct identity linked to her.