Compare two product titles and generate a comprehensive list of required changes for catalog synchronization

This title describes a business workflow rather than a complete algorithm, so establish the contract first: which catalog is authoritative, should case, punctuation, sizes, and brand aliases be normalized, and does word order matter? Preserve the raw strings for audit, then tokenize a normalized representation according to those agreed rules. A multiset comparison identifies added and removed tokens; ordered token alignment can identify replacements and moved phrases. Return a structured record such as normalized-equal, additions, removals, replacements, and a confidence/review flag, rather than mutating catalog data directly. Do not remove meaningful tokens like model numbers through aggressive normalization. Complexity is O(a + b) for multiset diff on a and b tokens, while sequence alignment is O(ab) when ordered edits are required.