Level of Absraction

• Physical Level describe how a record (E.X Costumer) is stored.
• Logical Level: Describe data stored in database, and the relationship among the data.

                          Type Costumer = Record
                                                                  Name : string;

                                                                   Street : String;
                                                                  City : integer;
                                                        End;

• View Level: application program hide details of data type.view can also hide information (EX. Salary ) for security purpose.