One principal, one session: a person logs in, authenticates, gets a role. Each action is attributable to that person.
Explicit credential hand-off: sharing credentials requires deliberate action — copy, send, type. It's visible. It leaves traces.
Session ends, access ends: log out or timeout clears the session. Credentials don't persist into the next person's session.
One level of delegation: a manager approves a task. The approver's identity doesn't travel with the approved action.
Many principals, blurred attribution: one agent acts for many users across many tasks. Who did a given action? The agent? The user? The operator?
Implicit credential sharing: an agent holds credentials in memory and can invoke them on behalf of any prompt it receives. Sharing is the default, not the exception.
State persists across sessions: agents can retain memory — including credentials — across sessions, users, and contexts unless explicitly cleared.
Recursive delegation: orchestrator delegates to manager, manager to worker, worker to sub-worker. Each hop can expand scope. There's no standard limit.