Explanation:

According to the Microsoft SC-300: Identity and Access Administrator official study guide and the Microsoft Learn "Implement and manage Azure AD Identity Protection" module, Azure AD Identity Protection detects two primary categories of risks: user risks and sign-in risks.
* User Risk Policy:A user risk represents the probability that a user's identity (credentials) has been compromised. Examples of user risk signals include leaked credentials, unusual sign-ins from different geographies, or sign-ins from infected devices. The Exam Ref SC-300 specifically lists "leaked credentials detected on the dark web or other compromised repositories" as the main trigger for a user risk policy. Such a policy can automatically force password change or enforce MFA to remediate the threat.
* Sign-in Risk Policy:A sign-in risk reflects the likelihood that a specific authentication attempt is not performed by the legitimate user. Sign-in risk is based on context, such as sign-ins from suspicious browsers, anonymous IP addresses (like TOR networks), or impossible travel scenarios. The SC-300 documentation highlights these examples as conditions best handled with a sign-in risk policy, where conditional access can block or require MFA for the risky sign-in attempt.
Therefore:
* Leaked credentials are addressed through a User Risk Policy, since the account itself is compromised.
* Sign-ins from suspicious browsers and access from anonymous IP addresses are handled through Sign- in Risk Policies, as they relate to risky sessions rather than compromised identities.