A PDA is a piece of online infrastructure that belongs to a person: All of the data is that person's property. A Contracted PDA on the other hand is half-owned by you, and half-owned by a business publishing data into it. An example would be salary and tax details provided to you by an employer's HR software. It is your private information, but the business has an obligation to store this one-and-only copy of your private data securely for a time, thus the shared legal ownership and rights. This applies on a specific folder/namespace and the folder is given joint rights of a PDA.
What this means in real world terms is, the PDA owner cannot cancel the data debit or contract without the publishing organisation's consent.
Other constraints would also apply. The organisation's data-processing and analytics will usually able to produce analytics or simply direct/merge information. Benefits of this solution include but are not limited to;
organisations having control of information pertaining to them in the organisation's folder via the contracted PDAs functionality
data that is shared with the organisation who may produce analytics to enrich enterprise systems to benefit wider organisation
Organisation can keep sensitive information within PDAs and give their own staff limited access to sensitive personal data as part of Dataswift's platform's credentials management.
Contracted PDAs have the functionality at the folder/namespace level. PDA owners are still private across all other folders in the PDA.