WHY DO YOU DISTINGUISH BETWEEN THE “DATABASE” AND ITS “CONTENTS”?

Answer:

The simplest answer is because they may have separate rights. For example, consider a database of photographs. Here there are the rights in the database and quite separate individual copyrights in the photographs. Or consider the example of Freebase which contains textual material and images from Wikipedia as well as user contributed material. While Freebase controls the database the individual items of contents need to have their own separate license.

Of course much of the time the the Licensor of the database is also in the position to license the rights (if any) in the contents — the classic example would be a database containing factual data. For this reason Open Knowledge Foundation created a very simple Database Contents License which you can use in conjunction with the ODbL to ensure that you’ve licensed everything.

To summarise:

1. For a homogeneous DB (No need to distinguish “Database” + “Contents” because you control rights in both or no independent rights in the “Contents”)

• For Share-Alike: Use Open Database License (ODbL) + Database Contents License (DbCL) (or some other suitable contents license of your choosing)
• For Public domain: Use Public Domain Dedication and License (PDDL) (it covers both “Database” and “Contents”)

1. For non-homogenous DB (need to distinguish “Database and Contents”):

• Share-alike: use ODbL for Database qua Database + whatever license you want/can for Contents
• Public domain: use PDDL for Database qua Database + whatever license you wish/can for Contents

https://opendatacommons.org/faq/licenses/