Which Are You: Proprietor, Custodian or User?
A Data Proprietor is the department director or senior manager who is the functional owner of the application that is the primary source of the personal information.
A Data Custodian is an individual that is responsible for providing technical or system administration support for the data store.
A Data User is an individual that must abide by established procedures on access to and use of protected data; and protect the resources under their control, such as access to passwords, computers, and the data they download.
A Custodian of Records (not the Data Custodian) - The Superintendent or designee shall designate a certificated employee to serve as custodian of records, with responsibility for student records at the district level. At each school, the principal or a certificated designee shall act as custodian of records for students enrolled. The custodian of records shall establish procedures which maintain the confidentiality of information contained in student records. (Code of Regulations, Title 5, 431)
In the end, we are all data users who must abide by the procedures to protect data.