What is a key characteristic of Roll-Up Summary fields?

Roll-Up Summary fields are specifically designed for use in master-detail relationships within Salesforce to aggregate values from related detail records. This characteristic allows users to automatically calculate and display a summarized value for the master record based on fields from the detail records. For instance, if a master record is an account and the detail records are contacts, a Roll-Up Summary field could be used to sum up the total number of contacts associated with that account. This feature enhances data management and reporting by allowing users to see computed information without needing to perform manual calculations or additional queries.

The aggregation of values from detail records is a fundamental purpose of Roll-Up Summary fields, setting them apart from other field types in Salesforce, which may not provide the ability to automatically summarize data in this way. This capability is particularly valuable for businesses that want to maintain real-time insights into related data without manual oversight.