A CDF file contains the same data that an Audience Manager event call (/event) sends to AAM servers. This includes data like user IDs, trait IDs, segment IDs, and all the other parameters captured by an event call. Internal Audience Manager systems processes event data into a CDF file with content organized into fields that appear in a set order. Audience Manager tries to generate CDF files hourly and stores them in a secure, customer-specific bucket on an Amazon S3 server. We provide these files so you can work with Audience Manager data outside of the limits imposed by our user interface.
Note: the "device" column is not IDFA or AAID. It is the demdex/aam ID. Perhaps that should be called out directly in the documentation. If you are looking for device ID's like IDFA or GAID, you are looking for an ID Sync data feed which has to be set up by account services.
It would be a great feature to expose the IDSync capability over to the clients so we can configure custom data feeds like we do with Omniture.