Matching Algorithms contain a set of SQL-like rules that determine whether the DR Key Properties of two records indicate a match, ie the source (new record being checked) and destination (existing record being compared) are the same Data Record.
Why Matching?
By default, if a matching algorithm is not specified, records are determined to match only if all of the values of their DR Key Properties are identical. Custom rules and/or score based matching Algorithms are useful for identifying duplicate records in different systems where some data may or may not completely match.