An understanding of the technical definitions is the first step in understanding the
provisions of any statute or statutory instrument. In this chapter each of the key
definitions in the Data Protection Act 1998 (the Act) is explained and the intricacies of
the technical and legal aspects of each is considered. Other key words and phrases that
are helpful in reaching an understanding of the data protection principles, but not
found in the Act, are also considered. Cross-reference to other definitions within the
explanatory text has been minimised where possible.