The concept of the publication is a way of associating documents that are logically related.
Different enterprises may see this in different ways:
- A publisher could see it as the issues in a subscription
- A training course provider could see it as the content of a course
- A lawyer could see it as the items making up a bundle
- A businessman could see it as the collection of documents making a bid
So, being able to bring together collections of documents to create a publication makes the administration of connected documents easier for the publisher and simplifies how they are used by the user. If you choose to publish your documents as separate items, then each one will have its own encryption key. However, where customers are purchasing subscriptions to publications they expect to register their subscription once and then be able to read each issue as it arrives. Also, you as the publisher may find it easier to associate documents with publications.
To meet this operational flexibility, if documents are protected as something in a publication, the encryption key of the publication is used to protect it rather than generating a new random key. This means that the customer is able to immediately use a new issue regardless of how you ship it to them (email, flash drive, CD-ROM for instance). Of course if you send them a document that is not part of a publication that they have been granted access to then they will have to connect to the administration server to retrieve the new key. If you set the rules so that they must connect before using your documents, then that will be enforced.