When you create a Segment in Ad360, you have the possibility of uploading a file containing IDS to populate this segment with pre-existing data.
You can do this either if you want to create a new segment containing user data that you've generated in the past or if you have 1st party data that you'd like to leverage with Ad360.
The IDs that you can upload in the document can be either:
Ad360 IDs (“uid”) for Web users; AND/OR
DeviceIds (“adid”) for Mobile.
Both types of IDs can be mixed in the document and belong to the same segment.