You can use fields and their definitions from a predefined table in your screen table definition to promote the shareability of data definitions. The use of definitions for screen fields simplifies coding and the assignment of data. If the screen fields match the table fields, you do not have to worry about matching the appropriate fields or leaving fields out.
Global fields are another type of predefined field that you can use in your screen table definition. Global fields are fields defined by your system administrator to be used system wide for all table types (TDS, RPT, SCR, and so on). Global fields are used to create standard definitions across the database. Global fields standardize the position, name, and how your fields use data across your screens. You can then customize the presentation of each field when you copy the field into your definition or at a later time.
You can create screen fields that contain default attributes. Using default attributes you can achieve the functionality of the field and customize the presentation of the field at a later time. Using screen fields with default attributes is useful if you want to use the field for testing purposes and are not concerned with the presentation of the field.
Creating new fields gives you total control over the data definition and the presentation attributes. You can create screen fields to your specifications. For information on creating new fields, refer to
Creating New Fields.