To connect Testimonial__c records with both the submitter’s Contact record and Account record, an app builder should create a master-detail relationship from Testimonial__c to Account and a lookup relationship from Testimonial__c to Contact. A master-detail relationship creates a parent-child relationship between two objects and allows for roll-up summary fields, sharing settings, and cascading actions. A lookup relationship creates a loose association between two objects and allows users to relate records from one object to another. Source