What is Identity Resolution in Data Cloud and how do deterministic vs probabilistic matching differ?

Identity Resolution (IR) unifies records from multiple data sources into a single Unified Individual profile by linking related Contact Point records. Configuration uses IR Rulesets:

1. Deterministic Matching — exact-match rules on high-confidence identifiers (exact email address, exact phone number, exact loyalty ID). High precision, lower recall.
2. Probabilistic Matching — statistical scoring across multiple partial signals (similar name + same city); matches records that are likely the same person without a single exact identifier. Higher recall, lower precision. Reconciliation Rules determine which attribute value "wins" when multiple sources provide different values for the same field: Most Frequent (majority value), Last Updated (most recent), or Source Priority (configured source order). The Match Rate Dashboard in Data Cloud shows the percentage of records resolved into unified profiles.