This need not be particularly sensititve information, and can be as little as a name and address. Automatically processed means, broadly speaking, information which is processed by computer. It does not cover information which is held and processed manually, e.g. in ordinary paper files. A data user can also be a sole trader, partnership, or an individual. A data user need not necessarily own a computer.
Data subjects the individuals to whom the personal data relate.
With few exceptions, if you hold or control personal data on computer, you must register with the Data Protection Registrar. Registration is normally for three years and one standard fee is payable to cover this period. Computer bureaux which process personal data for others or allow data users to process personal data on their computers must also register. Their register entries will contain only their name and address. Data users and computer bureaux who should register but do not, are committing a criminal offence, as are those operating outside the descriptions contained in their register entries.