If a user has access to a junction object but not the master-detail relationship, what will they experience?

The scenario revolves around how access permissions are structured in Salesforce, particularly in the context of master-detail relationships and junction objects. When a user has access to a junction object but lacks access to the master-detail relationship, it directly impacts what the user can see and interact with concerning the junction object.

In this case, since the user does not have access to the master record linked through the junction object, they will not be able to view the junction object records or the field values related to them. Salesforce enforces a strict policy where if a user does not have visibility into the master record, the associated records in the junction object become invisible as well. This is because the master-detail relationship is designed to reflect a strong dependency between the records, where visibility into the junction object is contingent upon having access to the master records.

This setup ensures that sensitive data within the master records is not exposed through the junction object, maintaining data privacy and integrity within the system. Thus, if the user can't view the master record, they are effectively blocked from seeing any related junction object records as well, confirming the validity of the provided answer.