I have a custom object called "Research" that has a "Notes and Attachments" section where users are to upload documents that represent research for that record. For other objects in our system, this process created an Attachment record whose ParentID pointed to the record to which the document was attached. On my Research object, however, these uploaded documents are getting stored as a ContentDocument. I have two questions:
1) Why is there a difference here? 2) How can I find out how my ContentDocument relates to my Research record? The ParentId of the relevant ContentDocument is null.