Why woulda developer use LookupRows Instead of the Lookup AMPscript function?

A developer would use the LookupRows function instead of the Lookup AMPscript function to return a complete rowset from the data extension (A). The LookupRows function retrieves all rows that match a specified criterion, returning a rowset that can be further processed or iterated over in AMPscript. In contrast, the Lookup function retrieves only a single field value from the first row that matches the specified criteria.