What is data privacy?

Data privacy is the relationship between collection and dissemination of data, technology, the public expectation of privacy, and the legal issues surrounding them.

Privacy concerns exist wherever personally identifiable information is collected and stored - in digital form or otherwise. Improper or non-existent disclosure control can be the root cause for privacy issues. Data privacy issues can arise in response to information from a wide range of sources, such as:

Healthcare records

Criminal justice investigations and proceedings

Financial institutions and transactions

Biological traits, such as genetic material

Residence and geographic records

Ethnicity
Internet privacy forms a subset of data privacy and consists of privacy over the media of the Internet: the ability to control what information one reveals about oneself over the Internet, and to control who can access that information.

Sources:
http://en.wikipedia.org/wiki/Data_privacy
http://en.wikipedia.org/wiki/Internet_privacy