A document in xSuite Archive Helix is a composite structure of properties, metadata, data contents and attachments. File contents of the attachments are not stored directly with the document but the reference to it.

Comments are stored separately in the comment service (not part of this API). The structure of a document is defined in DocumentDto. For the specific details of that class and all referenced schema objects see DocumentDto, AttachmentDto, etc. in OpenAPI specifications.