From LongJump Support Wiki
A Related Object is a participant in an Object Relationship.
If the record you are viewing has a Lookup field, then there is only one Related Object for that relationship (the record the lookup points to). But if the record you are viewing is the target of a Lookup, then many other records could be pointing to it. In that case, those Related Records are displayed in the Related Information section of the record you are viewing.
For example, in the Sample Order Processing System, records in the OrderItems object "look up" to records in the Orders object. When viewing an Order record, those records appear in the Related Information section. When entering an Order, the Form may display them in a Subform (a table of related records).
- From the standpoint an OrderItems record:
- Orders is a related object.
- There can be only one, so the identifying information for the Order is displayed as part of the OrderItems record.
- From the standpoint of the Orders record:
- There can be multiple related records in the OrderItems object.
- When you view an Order, the related records appear in the Related Information section of the Order form.